Here's a little DIY on how to replace your own spark plugs. Some people have reported Mazda dealers charging $300 for this (:Eyecrazy: )! For anyone wondering why I changed them, they were extremely fouled from the first 10,000 miles of driving (before L and M).


*EDITED TO ADD- Remove the driver's side wheel before starting*

#1 - Jack the car using a good hydraulic jack, placing a piece of wood between the jack and your frame rail. This will prevent you from denting the underside of your car. ALWAYS PLACE A JACK STAND UNDER THE CAR. THIS COULD SAVE YOUR LIFE!

# 2 - From underneath the car, you have a clear reach at the rear plugs. I recommend breaking them loose with the wrench, but then removing them by hand. Not only do you avoid banging your knuckles on everything, but it goes faster.

Once removed, your plugs will look something like this. Clean them in your preferred method.

For the front rotor, the plugs are tough to reach. Next time, I will remove the driver's side wheel, but since I didn't have my lug key with me, I still reached them by turning the wheels all the way to the right. Behind the wheel, remove the upper fastener on the rubber splash "thingy". (Oooohh....Technical terms! :D ) This is NOT a screw, but one of those that only requires a quarter turn to release it, similar to the clips on your wheel well liner. Once it pops out, gently pop out the washer by sliding a flat head screwdriver under it and twisting gently. Did I say gently? Seriously people, these things beak easy.

If you've got skinny arms, you CAN use this method, but as I said: Take the wheel off.

3

The front plugs are now visible.

When reinstalling the plugs, be sure to apply a light coat of anti-seize to the threads.

Each plug is marked with a T or an L, which indicates leading or trailing. It is VERY important they are reinstalled correctly. Double check this, and note the T and L cast into the side of the motor beside each hole. Match these up.

Also, you did notice that the trailing plug wires are marked with green and blue tape, right? If not, make sure upon reinstallation that you attach them correctly.

That's it! I haven't even taken the car out yet to see if it helped, but at least I know how to do it now.

REMEMBER: SAFETY SAFETY SAFETY WHEN WORKING UNDER YOUR CAR!!

Nice DIY man. :D

Nice illustration ... job well done.

Sure it is dirty.

Is there any spark plug better than what we use? We use NGK Iridium right?

factory plug is the best. check out silverbullet.com for a write up on plug test on an Rx7. These factory plugs are really expensive so I guess cleaning is justified but I wouldn't reuse them too much. Plugs can crack under the high heat of a rotary engine if they become old.

I was not able to thoroughly clean the plugs.

I removed the carbon on the top surfaces, but without a sandlblaster, I couldn't get down to the bulk of the gunk that was deep inside.

It DID make a noticeable difference in throttle response and bottom end. The car pulls smoother, and the loss of power at 7K is gone. However.... The knock is still there. I think new plugs would do the trick, because it is lessened after the partial cleaning of the plugs. Mazda needs to step up and replace plugs on cars with several thousand miles on them before L was released. I doubt they will, though.

My plugs were replaced by the dealership under warranty at 12k miles, because I had a random misfire. Maybe you can get them to replace yours?

Originally posted by Tony Orlando
I was not able to thoroughly clean the plugs.

I removed the carbon on the top surfaces, but without a sandlblaster, I couldn't get down to the bulk of the gunk that was deep inside.

It DID make a noticeable difference in throttle response and bottom end. The car pulls smoother, and the loss of power at 7K is gone. However.... The knock is still there. I think new plugs would do the trick, because it is lessened after the partial cleaning of the plugs. Mazda needs to step up and replace plugs on cars with several thousand miles on them before L was released. I doubt they will, though.

Few notes on this -

First off, VERY GOOD call on coating the threads of the spark plugs with anti-sieze. If you do this, when you go to remove the plugs later, you just break them loose then remove by hand. Don't do this, and you'll be there a half hour with a piece of pipe over the socket wrench, turning it a quarter turn at a time. Our convertible RX-7 had monkey-installed plugs, and I didn't think I was EVER going to get the #1 leading plug out.

For the time being, the RX-8's iridium plugs are the best thing going. The old copper or platinum NGK's the RX-7 used might be worth a try, but I think life would be a lot less, and I don't know if it would cause any driveability problems. They ARE a helluva lot cheaper, though - $5.99 for the coppers each, and about $8 or so each for the platinums.

On the plug wire markings - best case scenario, you do want the right wire going to the right plug. But, the leading plug wires, if the ignition fires like the RX-7 did, are swappable - leadings fire at the same time. Trailings don't, and swapping the trailing wires will result in detonation, which is hella bad on a rotary :). Long story short, it's a REAL good idea to make sure you've got the plug wires on right. The stock NGK wires are marked, but aftermarket wires might not be - probably would be worth marking them.

I have seen little spark plug cleaners before - it's a small doober you hook up to a compressed air source and it has sandblasting sand (or the like) in it. Screw in the spark plug, hook up air, squeeze the trigger, done. Dunno how well they work, or if they'd cause a problem with the iridium plugs (doubtful).

You'd be VERY suprised how many problems can be solved with a fresh set of plugs. I've seen people buy cars WAY cheap just because the plugs were fouled - the owner thought the motor was blown.

Does the '8 use different heat range plugs for leading and trailing? I'd reckon so.

Dale

Is swapping out the plugs and letting the engine sit for a bit with the holes open a reliable way to de-flood the car?

Not in particular. Best is to find some way of disabling spark and fuel - probably pulling the ECU fuse or the like, then cranking the engine over for a second or so to blow all the fuel vapor out.

You have to be REALLY careful with this, as atomized fuel is VERY flammable. You have to be certain the spark is disabled, as the disconnected spark plugs could ground to something and ignite the fuel in the air.

Dale

Where did the pics go? Yes I realize how old the write up is, anyone have a newer version?

Can you not reach the front rotor plugs from under the car like the back rotor?

Pictures have been missing on other "older threads". I believe it was due to some server problem. Contact a moderator and they may be able to restore them.

Yes, all the plugs can be reached from the bottom. No need to remove the wheel.

testing to see if adding another pic will fix the old ones....


Yep, that seemed to do the trick

Thanks Nubo! - for restoring the pics.
and Tony - for a great DIY post - I just finished copying that all to a single document...<g>

One thing, though... On my '99 Solara, Toyota called for double tipped NGK plugs that were gawd awful expensive (maintenance interval was 70K miles!) - I believe they were iridium as well - I seem to recall a note in the package about _not_ cleaning these b/c the plating on the electrodes could be damaged...
Anyone else have any background on this?

Do you have to use a special socket for these plugs, or are they just like any other plug?

Do you have to use a special socket for these plugs, or are they just like any other plug?
When I did mine last week I used a regular 5/8” spark plug socket (pretty sure it was 5/8") Having at least a 12" ratchet extension helps also.

Thanks just wanted to make sure.

Just received my new plugs from sparkplugs.com and noticed the part # for the leading plug was different than what is called out in the workshop manual. It also has notches in the end that I hadn't noticed in any pictures before.
RE7A-L vs. RE7C-L

The following explains the difference (copied from sparkplugs.com)

NGK: Racing plug

14mm thread, 21mm reach, 20.6mm(13/16") hex, 62mm height, Trailing plug, solid terminal, notched shell aids cleaning, fine wire, (.08mm) iridium center electrode, fine wire platinum ground electrode .048" gap (1.2mm)

Original equipment, fine wire plug designed to give you optimum spark from your existing ignition system. Slightly recessed fine wire iridium center electrode requires less voltage to ionize(jump) the plug gap. This allows a stronger spark which will better ignite the air fuel mixture leading to more power. The iridium center and platinum ground electrodes for extreme durability. Fine wire platinum ground electrode to reduce quenching. This plug is improved over the RE7AL as the shell has been notched to reduce fouling and improve cold starting.

NGK Racing plug 6700 RE7CL $19.95

I'll be putting these in tomorrow morning. My car is a December, 2003 build date with 30K miles and has had several different flashes.

That does look different than any other plug I have seen on this board. Let us know if you have any issues with them.

Those are what FD plugs have looked like for the past couple of years.

Laters!
Edgardo

So Low Fly'n have you had any issues yet? have you noticed any improvement?

Whooo!

I was about to take my car to the dealer for the 35k service - decided to call first and ask the price..... $799.95

I said "WHAT? - you've got to be kidding!"

He proceeded to list what would be done. The plugs alone (installed) were $300. SO flushing the coolant, changing brake fluid, air filter, checking a whole bunch of "no real work" things was costing the rest ($499).

So I am doing the plugs (and most of the rest) myself like I did with myold RX-7. But I am a little confused about the spark plugs that you guys are recommending:

Are you guys recommending the $20 one from sparkplugs.com?

Also - the coolant looks good and has never leaked - should be good for a little longer -correct?

And the brake fluid - I normally replace at 4 years old.

Any commnets?

Check the manual, I believe all you have to do is check the coolant at 30k, not actually change it, but I don't see what it would hurt to change it. That would probably would cost you $10 or so and an hour of your time.

The plugs you want are the NKG ones on www.sparkplugs.com, and yes they were $20 a piece on that site, you will need to leading and 2 trailing plugs. That will probably take you an hour to do as well.

I would think as long as the break fluid still looks kinda light gold you are good.

I replaced my plugs about two weeks ago using the illustrations posted by Tony. I also purchased the $20 Iradium plugs at sparkplugs.com. I found as did "Low Fly'n" shown in his/her image that one set of plugs were different looking also. My "8" has 41000 miles and is just 14 months old. After changing the plugs I have driven about 800 miles and the car runs great. I have had no problems starting her up, she idles at a constant rpm and performs like new. The replacement procedure took me about 45 minutes. I personally think jacking her up, removing the drivers side wheel is the way to go. All four plugs are easily accessible from there. I also installed a new K&N air filter, again no problems.

Excellent - thanks for the advice guys!

Feliz Navidad!

So Low Fly'n have you had any issues yet? have you noticed any improvement?

The car is starting / running perfect just like it always has. I have only used 93 octane Ammoco Gold from day one and have never flooded. The plugs I removed @ 30,000 miles looked good to go and could have easily gone a couple thousand more miles.

I think the latest flashes are keeping the plugs cleaner and burning better than the first flashes.

Just changed the plugs using Tony's illustrations. Thankfully, I read the "remove driver's side wheel first" part and that made all the difference. I bought the NGK plugs from sparkplugs.com and had a great purchasing experience.

Great Job Tony!

Just FYI, we're having a Group Buy in our forum on the OEM NGK plugs for $86 shipped. I'm realizing that this isn't a great savings over sparkplugs.com, but it should at least match them when shipping is included or beat them by a couple dollars.

And good work on the DIY, Tony!

Do you think replacing the sparks with new ones or cleaning them could make the 8 idle smoother?

When warm, at idle it sounds like an old 4 bannger and the car shakes quite a bit! Much so that at night when I am standing behind another car at the lights I can see my headlights shaking up and down on the front car's bumper.

Once you get the revs up its smooth as a baby's bottom.

You will only know if you remove the plugs and check them for fouling. If the center insulators look grey or black, replace them, or if you have the capability, clean them. If the center insulator is a white or brownish color, you're good to go. The center insulator is the key and any crud elsewhere is generally just a cosmetic problem, although it doesn't hurt to clean that up while you're at it.

Edit: the red area of the center insulator is what you want to see a whitish or brownish color.

has anyone tried a hotter plug?

One thing that has been missing from this thread -

Does anybody know the torque spec for tightening the plugs?

:wavey:

easiest way to change all four is through the drivers wheelwell, undo the rubber shield and you have clear access to all four

Yup, that's exactly what I did.

Thanks for the torque spec.

Still missing that 7500 rpm kick, though...

do you guys know what the spark plug gap is for rx8s????
i am afraid of taking my spark plugs out because i don't know the gaps??

Standard [both]: 1.15mm-1.25mm (0.046-0.049in)
Maximum: Leading 1.5mm (0.059in) Trailing 1.4mm (0.055in)

Thanks for the great guide. This site and it's posters have been an invaluable resource to me. I just ordered in the plugs from Sparkplugs.com (http://www.sparkplugs.com) and wanted to mention there is a code using the word nicoclub at checkout.




Discount (nicoclub - 10% off NGK or Denso order over $25 ):

What's wrong with using oil on the plugs threads?

I've always done that.

The problem is that oil gets thick and sticky over time, especially when exposed to high temps. And if the sticky oil causes the spark plug threads to adhere to the housing threads, you may remove a plug and leave the threads in the housing. In other words, the spark plug threads may strip off and you get a plug that is nice and smooth where the threads used to be and the threads remain in the housing. I've seen it happen in a boinger and man that is a REAL pia to repair.

Get some anti-seize compound at your local parts store. It's cheap insurance.

You need 3 long extensions.

One of the extensions need to be a wobble. Similar to swivel, but it's a wobble.

You need 3 long extensions.

One of the extensions need to be a wobble. Similar to swivel, but it's a wobble. Like this, you can find a cheap set at http://www.harborfreight.com/.

How many miles on the old ones? What did they look like>

How many miles on the old ones? What did they look like>Looks can be deceiving with our plugs.
http://www.rx8club.com/showpost.php?p=1529059&postcount=312

Followed this guide to get my spark plugs removed today. Boy that front Lead plug on the bottom was a PITA to get off.

Once all four were removed, (and marked to not mix up their locations) I noticed that were absolutely filthy. Fouled up with an almost acidic looking brown substance.

I don't have an actual spark plug cleaner, so what I do is attach a metal brush drill bit to my power drill, clamp down the spark in a press, and steadily grind away that build up. The tops look as good as new now, but the inner portion of the spark plugs are still bad.

After reinstalling and taking the car for a drive, I noticed a smoother ride, less popping, but the car still idles funny. I'm going to purchase some new plugs next weekend. Probably the NGK brand.

Great DIY though. Just wanted to say that.

Brown is good--black or white is not. Brown is not fouling.

About the tigthening procedures:

In the box of a NGK sparkplug RE8C-L that is just in fornt of me one can read the following "Tighten the spark plug with finger first, then screw about 1/2-3/4 (Conical seat plugs: about 1/16) turn more with plug wrench."

I guess that that is equivalent to the torque tightening procedure which figures have been provided up this thread.

Now the following question about sparkplug tightening: whether in angle or in torque is it there any noticeable influence in combustion going to the "loose" limit compared to the "tight" limit?

Cheers

jird20

If they are "loose" enough that the gasket is not sealing, the effect will be loss of compression and reduced engine performance. Why not spring for a torque wrench and do the job correctly?

FYI: Was at Auto Salon in Tokyo last weekend and HKS had special RX-8 plugs on show that they will release in Feb. No price info yet.

Tom.

If they are "loose" enough that the gasket is not sealing, the effect will be loss of compression and reduced engine performance. Why not spring for a torque wrench and do the job correctly?


If you use anti-seize or oil on the threads, a torque-wrench will cause you to overtighten the plugs.


Not to mention, with the leading plug, if you go in too far...you run the risk of the apex seal catching the tip of the spark plug...

Great walk through, helped me out since I'm not a car guy and typically just let the dealership do their thing when I need something done. I read the guide then went and did it myself, took me about 2 hours to do all 4. You know it makes you feel closer to your car when you work on it yourself...

When I did mine last week I used a regular 5/8” spark plug socket (pretty sure it was 5/8") Having at least a 12" ratchet extension helps also.

I just tried my 5/8 plug puller way to small! Its 13/16 spark plug socket, or the metric equivalent

benfura: I'm in the middle of this right now and the 5/8's just doesn't seem to fit .... damn...

just got back from the auto parts store. 13/16 is working like a charm...

All 13b's Use The Same Plugs - Or At Least They Can , Im Using Rx7 Plugs In My 8 - They Are 9 Each And Last Upto 9 Months - Also , I Use 4 Of Them "9" - Instead Of The 2 ''7"s And 2 "9"s - Instead Of Two Leading And Two Trailing . This Gives You A Much Colder Ignition , Great For Fi

I've heard iridiums are not supposed to be cleaned due to the coating on the tip. Anyone confirm or deny this? Either way $80 to replace the plugs every 37K miles isn't bad.

So my parents call me about the rx8 that they have. My mom flooded it and my dad was trying to take the spark plugs out and they droped the spring that is in the spark blug wire/boot. That's how they explained it to me. Does anyone know how to get it back together?

Game Over, Thats all I gotta say.

That helps me very little. Thanks for the meaningless post. Anyone else got any ideas. They already took it to the shop. I was just wondering in case this happens again.

About a month or so, I bought a new '06 and there were 4 new plugs in the glove box. I assumed that these were supposed to be an updated plug that should have been replaced due to a recall or something and that the dealer just never got around to doing it. However I've not found anything as far as recalls for this on the '06.

Is this assumption correct about the recall or did I just get 80 bucks worth of spark plugs for no reason?

About a month or so, I bought a new '06 and there were 4 new plugs in the glove box. I assumed that these were supposed to be an updated plug that should have been replaced due to a recall or something and that the dealer just never got around to doing it. However I've not found anything as far as recalls for this on the '06.

Is this assumption correct about the recall or did I just get 80 bucks worth of spark plugs for no reason?

Dont worry about it until it is a problem.

There is no use in replacing the spark plugs if you are not experiencing:
loss of power, crappy idle, or hard starts.

About a month or so, I bought a new '06 and there were 4 new plugs in the glove box. I assumed that these were supposed to be an updated plug that should have been replaced due to a recall or something and that the dealer just never got around to doing it. However I've not found anything as far as recalls for this on the '06.

Is this assumption correct about the recall or did I just get 80 bucks worth of spark plugs for no reason?
The plugs were supposed to be installed prior to delivery of the car. Nothing to do with a recall. If you do a search on the forum you will find that at one point, Mazda realized that some new cars were flooding due to multiple cold shutdowns when moving the cars off the boat and around the lot prior to their sale. So, Mazda put the new plugs in the glove box and instructed the dealers to install them just prior to delivery of the new car to the buyer.

Wouldn't hurt to go back to the dealer and have them installed like they should have been before you got the car. Or you can do it yourself using the instructions in this thread. That way, if your car is one of those that got shutdown cold multiple times, it will decrease the odds that you will have to deal with a flood in the future.

Dont worry about it until it is a problem.

There is no use in replacing the spark plugs if you are not experiencing:
loss of power, crappy idle, or hard starts.

That's pretty much the approach I was thinking I'd take. I really didn't want to crawl under the thing to see if the were different plug numbers or not.

So my parents call me about the rx8 that they have. My mom flooded it and my dad was trying to take the spark plugs out and they droped the spring that is in the spark blug wire/boot. That's how they explained it to me. Does anyone know how to get it back together?
Hmmm ... the only springs that I know of are in the spark plug wire connectors of the coils. The coils have a hard rubber boot that covers a metal spring-contact for the spark plug wire to fit into. Sometimes, the spark plug wire gets stuck to the coil connector boot and it comes off --- then the spring-connector pops out. All you have to do is take the coil boot off of the end of the spark plug wire, place the spring-connector into the coil, and then press (firmly) the boot back on the coil. Sounds like your dad was pulling on the wrong end of the spark plug wire :( .... unless he was also trying to replace the plug wires.

Cool- Nice to see that my thread is still helping people out around here.

If you use anti-seize or oil on the threads, a torque-wrench will cause you to overtighten the plugs.

Not to mention, with the leading plug, if you go in too far...you run the risk of the apex seal catching the tip of the spark plug...

Is this really a risk? As in "Do you need to get them dripping with anti-seize and overthighten them like a madman and almost ask for it for it to happen" or as in "Anyone not an expert risks killing the seals simply by changing the plugs for the first time" ?

:sweatdrop

I just did my second plug installation yesterday. Used anit-freeze (thin coating) and torqed to the specified 130 or so INCH-lbs both times. Never had a problem with rotor interference, and the old plugs (the ones I installed about 1 year ago)came right out.

I just did my second plug installation yesterday. Used anit-freeze (thin coating) and torqed to the specified 130 or so INCH-lbs both times. Never had a problem with rotor interference, and the old plugs (the ones I installed about 1 year ago)came right out.

Thansk GeorgeH :)

I was looking at the engine bay and figured I might be able to replace the coils without actually undoing the whole intake... simply removing the intake resonator (square-like box attached to the side of the intake tube, pictured here (http://www.rx8club.com/showpost.php?p=1445625&postcount=1)) might do the trick.

Anyone knows a good reason why I shouldn't touch that? From what I understand it's simply an empty plastic box connected to the intake tube...

Thanks! :)

Yeah, it's harmless!

S

Yeah, it's harmless!

S

Wow thanks for the ultrafast reply StealthTL ;)

A quick stop to get a 13/16 socket tomorrow and I'll be on my way for new (revised) coils, racing beat wires and brand new plugs. Can't wait! :)

FWIW, I just did my coils as well. I just loosened the phillps head screw that secures the plastic intake tube to the TB, pulled the tube off the TB and nudged the whole thing out of the way. It's flexible and you can move it easily. Oh, and I also pulled the strut bar.

It was still a tight pinch, but I could get the coils out, although if you have big hands this may not be enough. To get the connectors off, squeeze them at the end where the wires are, and pull - they shold come off easily.

George

Sweet. I'll be doing mine befor road trip :) Thanks for the DIY!

I bought my 04 RX8 this past Feb and have not done anything to it yet. I am approaching 30k and am going to replace the spark plugs. With all that I am reading I will be buying the NGK plugs. The question I have is has anyone bought aftermarket wire to go along with it? I am having trouble figuring out if I should buy some new ones. Any thoughts on Nology Hotwires?

Aftermarket wires are more for appearance on a stock engine. You won't notice any HP increase.

Aftermarket wires are more for appearance on a stock engine. You won't notice any HP increase.

True enough about the power, but Mazda OEM wires aren't the best quality, in my opinion. I had a one go bad, which resulted in a rich condition which subsequently killed the cat (and a coil). Now, it may have been the ham-fisted mechanic (me) who did the first plug swap that caused the eventual bad connection between one wire and one plug, I don't know. But I've been burned before by cheap Mazda OEM wires (older Miata, where wires going bad at 30k was/is a known issue) and decided to put on some Magnacores as insurance. Glad I did and I think it's worth the $$$, just from a quality standpoint.

Aftermarket wires are more for appearance on a stock engine. You won't notice any HP increase.

You think this is a game ? which wire will actually give you gains ?

Its more like for the sakes of your engine, better wires gives ya cleaner/better singals.

If you work on audio systems long enough you will know that wires quality makes a BIG difference.

The coils was easy to replace. Just a few bolts and everything came off. But I have K&N version 2 so it makes it easier.

Plugs are a bit harder, at least I have to jack my car up.

Just received my new plugs from sparkplugs.com and noticed the part # for the leading plug was different than what is called out in the workshop manual. It also has notches in the end that I hadn't noticed in any pictures before.
RE7A-L vs. RE7C-L


NGK: Racing plug

14mm thread, 21mm reach, 20.6mm(13/16") hex, 62mm height, Trailing plug, solid terminal, notched shell aids cleaning, fine wire, (.08mm) iridium center electrode, fine wire platinum ground electrode .048" gap (1.2mm)



NGK Racing plug 6700 RE7CL $19.95




So is this the trailing or leading plug....you mention both but never distinguish betweeen the two????? You say leading but the description says trailing?????

good info, ill refer to this when i do my plugs

bump because I want to thank everyone that contributed to this thread, as I just replaced my plugs using the information here. the torque spec was extremely helpful, and going through the front driver wheelwell made all the difference.

but when I pulled the old plugs, I noticed when the dealer (Rosenthal Arlington) did the starter/plugs/battery recall, they installed the plugs on the front rotor backwards (leading in trailing position, trailing in lead position), and the car actually drove normal for all this time (~30k miles). Kinda annoyed me that a Mazda dealer tech don't know how to installed the plugs in correction positions.

nontheless, car feels much better now. and here's the requisite pic of the old plugs lol

How possible is it to bend the plug holes?

I took my plugs out to check them, but I couldn't find my wobble extension at the time. It was a bit of a pain in the ass but I managed to get them all out with just straight extenders.

Now when I try to put the front leading plug in (I bought another wobble extender) it will only catch the thread on the plug hole if the plug is at a slightly downward angle. I can't hand tighten it much more than a few turns and it's way too tight to try to force it even close to flush with a ratchet. When it is slightly in, I noticed it's at a different angle than the rear leading plug (fully threaded).

I have switched my front and rear leading plugs and they both work in the rear hole, so I'm pretty sure it's the plug hole.

Any help would be appreciated. I'm charging my camera right now so I can take some pics.

Bump for pics.

http://i25.photobucket.com/albums/c92/polodoggie/1.jpg

http://i25.photobucket.com/albums/c92/polodoggie/2.jpg

So... any takers?

wow, that sucks. you going to take it in?

probably broke the ceramic insulating element. I would just use the wobble thing and take them out.

Best tool for this is magnetic spark plug socket, their about $10 at any auto parts store.

Pretty essential if you ever plan on replacing spark plugs yourself, once you use it you will wonder why you never started using it in the first place.

http://ecx.images-amazon.com/images/I/21KXDXDRHTL._AA200_.jpg

I left the spark plug on the edge of the hole just to keep the elements out. I have a spark plug socket and it's not hard to get at with the wheel off, the wobble joint on the ratchet and the spark plug socket. Maybe I'll check out the magnetic socket - I like tools.

Anybody have more information on the ceramic insulator? I took a good look in there (better than the pics, which were to show the difference between the front and rear plugs) and didn't see anything obvious. This is starting to sound expensive.

probably broke the ceramic insulating element. I would just use the wobble thing and take them out.

Best tool for this is magnetic spark plug socket, their about $10 at any auto parts store.

Pretty essential if you ever plan on replacing spark plugs yourself, once you use it you will wonder why you never started using it in the first place.

http://ecx.images-amazon.com/images/I/21KXDXDRHTL._AA200_.jpg

Staticlag,

Re-read his post and tell me what you think again?
Did you think he snapped the plug itself or is there a threaded ceramic insulator in the housing holes?
I thought that when he puts the new plugs in(I think he's saying that even if was to start by hand) that it is at a funny angle and gets tight way too soon. I think this means that the original old ones were probably cross-threaded and that's not good at all????? We know what he'll have to do in that case.
He should wait for other responses, but his choices are few..............if I read it right.

1.) Crank down how it is and hope for the best
2.) Re-tap the holes? Ugh!

Don't do either of these on my advise please. I would want to try it myself before making any real judgements!

I thought that when he puts the new plugs in(I think he's saying that even if was to start by hand) that it is at a funny angle and gets tight way too soon.

Yep. I thought he might've been talking about a ceramic insulator inside the plug hole itself because I tried two different plugs in the hole. Neither works in that hole but both work in the other.

Thanks for any assistance. It's not my only vehicle so I don't have to rush this, I was just worried/pissed when the spark plug wouldn't go in easily so I came on here for guidance.

Oh, and at this point I'm going to save cranking down and hoping for the best until all other options are explored. I did think about it though.:banghead:

Oh, and at this point I'm going to save cranking down and hoping for the best until all other options are explored. I did think about it though.:banghead:

Yeah.....don't!

I just don't know yet, but I don't think there is any insulator in the hole itself(esp. ceramic), but I really don't know. If there isn't, then you have to agree with me that the old plug might have been cross-threaded................right?

I don't know. I had to crank on it pretty good but I thought it was because I didn't have the wobble needed to get me around the slight bend.

I'm just hoping that when cranking on it I didn't bend the plug hole, but that's what seems to have happened. I need to do more research.

Staticlag,

Re-read his post and tell me what you think again?
Did you think he snapped the plug itself or is there a threaded ceramic insulator in the housing holes?
I thought that when he puts the new plugs in(I think he's saying that even if was to start by hand) that it is at a funny angle and gets tight way too soon. I think this means that the original old ones were probably cross-threaded and that's not good at all????? We know what he'll have to do in that case.
He should wait for other responses, but his choices are few..............if I read it right.

1.) Crank down how it is and hope for the best
2.) Re-tap the holes? Ugh!

Don't do either of these on my advise please. I would want to try it myself before making any real judgements!

Hmm, i just re-read the post and it does sound like he cross-threaded the first part of his plug hole. That sucks.

Probably the safest thing that you could do is re-tap the hole, but that size of tap is probably going to cost some cash.

Personally I would just line that spark plug up the best that I could and force it to go back in straight.

Its always good to thread anything in at least halfway by hand before using tools. I learned that the hard way a few times.

That doesn't sound good at all! It does sound like a cross threaded hole!

Okay, so I see Staticlag re-read and now agrees that it might be that the old plug was cross-threaded by the last monkey(dealership?) that did the plugs.
Cromax agrees as well.
Hard to tell you what to do from here, because none are real good. I would be tempted to take my sweet ass time, get comfy as you can, and try to put that plug in by hand and get it to line up straight. At least get it started straight and by hand!

hello averyone!!!! and which are going to be the best spark plugs for my stock 6 gear ? the stock one or any iridium sparks? something else maybe? i want the best one for my car please!!!!!

the NGK OEM plugs are your best option. They're some pretty damn good plugs. :)

OK dimitiris, I'll let you ask that same question just ONE more time, then that's enough.

.....pick a forum.


S

has anyone heard about those plasma coil-over-plug things? im wanting to make a high horse N/A engine... not sure exactly how... i figure... ignition, fuel, intake, and exhaust are about my only options there

If you want any real HP gains you have to look to forced induction or nitrous. You aren't going to get more than 20HP without spending serious bucks otherwise.

has anyone heard about those plasma coil-over-plug things? im wanting to make a high horse N/A engine... not sure exactly how... i figure... ignition, fuel, intake, and exhaust are about my only options there


The only HP increse that is real will be the Mazsport ignition solution.

For $600 you get 11rwhp on a bone stock 8. That is VERY good value in my opinion. Especially since we dont get any hp gains from intakes or catbacks.

The stock coils will fail on you eventually so the upgrade is well worth it!!

awesome DIY, took 15min to change the plugs after reading this. Hell of a lot better doing it myself than paying the dealership.

thanks again

i'm still kinda lost with the 'wobble' deal. anyone care to elaborate?

A universal joint in the socket drive, or a drive with a taper that will let the socket 'wobble'.....

S

A universal joint in the socket drive, or a drive with a taper that will let the socket 'wobble'.....

S
heading to the parts store in a few, thanks for the quick reply S!

Or wobble extensions.

My plug's stuck. I bought two 10" extensions and a wobble, but I can't get even the first plug out.

I'm all out of ideas. What do I do? I do think that the plug has seized... The last guy who did it had the strength of many apes...

You need Spark plug socket. It makes removal 100 times easier.

I'm thinking he's already using a spark plug socket.

For anyone that lives on the West side of Atlanta and doesnt want to bother with paying Mazda 300+ for new plug installs and lives close to Carrollton or Dville area, I will do the job for you for about half the dealers charge if you are on a budget. I just charge 150 and that includes plugs and everything. I hate to see people get ripped off by Dealers. I also know what it is like to be on a budget and, for those that do it yourself, always use antisieze and relplace them about every 10 to 15k miles. If you are having problems getting them to loosen, chances are, they didnt use antisieze or didnt know what they were doing. Good luck on getting your plugs out.

For anyone that lives on the West side of Atlanta and doesnt want to bother with paying Mazda 300+ for new plug installs and lives close to Carrollton or Dville area, I will do the job for you for about half the dealers charge if you are on a budget. I just charge 150 and that includes plugs and everything. I hate to see people get ripped off by Dealers. I also know what it is like to be on a budget and, for those that do it yourself, always use antisieze and relplace them about every 10 to 15k miles. If you are having problems getting them to loosen, chances are, they didnt use antisieze or didnt know what they were doing. Good luck on getting your plugs out.

Thanks Cliff for offering your RX8club fellow members such a "great" deal. If you can get the spark plugs for $60 to $80, then you're pocketing $70 to $90. Why don't you let the people buy their own spark plugs or buy them from you, then do the labor for FREE? They can buy you a pack of beers.

Spark plugs are 90 shipped. That is my cost plus a little anti sieze that is like a dollar. The other 50 almost 60 is the labor. Dealers charge about 90 and hour and even other places other than dealers charge 60 to 80. The difference is, I will travel to where you are if needed. I am just saying for those that dont want to do it themselves. If you can find a better deal other than doing it yourself, by all means do it. 150 is better than the dealer by half or better. The plugs from a dealer are 220 and that is a fact. 90 for the plugs cause they are 20 a piece + the 9 and some change for shipping + about 60 for labor. It is a good deal as it is fair. Many people on here cannot even change them out themselves due to people and/or dealers not doing it right by forgetting the antisieze ( hense the thread)

90 an hour for dealership is freaking cheap ! Hell in NYC, they charge at least 110 bux. problem is they still cant fix it right. :(

Dealerships dont put anti-seize in them ... cuz all they do is follow the service manual. Just like a dog listening to your *Sit* *Hand*

Spark plugs are 90 shipped. That is my cost plus a little anti sieze that is like a dollar. The other 50 almost 60 is the labor. Dealers charge about 90 and hour and even other places other than dealers charge 60 to 80. The difference is, I will travel to where you are if needed. I am just saying for those that dont want to do it themselves. If you can find a better deal other than doing it yourself, by all means do it. 150 is better than the dealer by half or better. The plugs from a dealer are 220 and that is a fact. 90 for the plugs cause they are 20 a piece + the 9 and some change for shipping + about 60 for labor. It is a good deal as it is fair. Many people on here cannot even change them out themselves due to people and/or dealers not doing it right by forgetting the antisieze ( hense the thread)

You wouldn't do it for free even if the person took you to Clermont Lounge to see Blondie?

Great DIY.
Just replaced my plugs.

Atlanta area is not quite as expensive as the NYC area. I was quoted over 300 for mine at Jim Ellis. I thought to myself, I better read and learn how to do it myself as I am somewhat mechanically inclined. I have worked on other cars that I have owned in the past. If the dealer doesnt use antisieze then, it is just going to be a mess especially if you wait a little bit before changeouts. The first time I changed mine out, it was a little difficult but, now, it is relatively easy. Using antisieze makes it so much easier. I recommend people that own the cars to do it themselves but, for those that cannot/wont do it, I can. Startl Respons, I will do yours for a dyno run. How is that? I am actually going to do a run tomorrow morning in Atlanta. Hope everyone has a great day and keep your plugs changed about every 10-15k miles and it will run good.

Atlanta area is not quite as expensive as the NYC area. I was quoted over 300 for mine at Jim Ellis. I thought to myself, I better read and learn how to do it myself as I am somewhat mechanically inclined. I have worked on other cars that I have owned in the past. If the dealer doesnt use antisieze then, it is just going to be a mess especially if you wait a little bit before changeouts. The first time I changed mine out, it was a little difficult but, now, it is relatively easy. Using antisieze makes it so much easier. I recommend people that own the cars to do it themselves but, for those that cannot/wont do it, I can. Startl Respons, I will do yours for a dyno run. How is that? I am actually going to do a run tomorrow morning in Atlanta. Hope everyone has a great day and keep your plugs changed about every 10-15k miles and it will run good.

Hell no, Cliff, if you've been reading threads around here, you'd know that I am now a super expert on doing spark plugs (and deflooding).

And people don't need to do their plugs every 10 to 15K. Every 35 to 50K is more like it. The only thing positive about doing it every 10 to 15K would be to your pocketbook.

Dont know why you are on my case about this. Super expert, in your own mind I guess. Deflooding is required when you dont let the car warm up properly. In the 30k miles I have had my car, not one time have I flooded my car. If you change your plugs out relatively often you will get better milage and keep better power numbers if you dyno it often. If you dont drive the car often or put many miles on it, 30k would be really pushing it as it would have a fair amount of build up on the end of the plugs. Believe what you want, I really dont care but, I do know what I see on my own car. I have talked to people that specialize in rotaries and, they say/do the same. If your car can get by on 35-50k miles, good for you, but I would rather change them more often just like Mazda says 7.5 on oil change. I change every 3000. Do what you want to but, my offer is cheaper than you will find anywhere unless you take labor out of the equation. I encourage people to do it themselves so they know it gets done right. The more people understand the rotary, the less skeptical they are about them.

hi all great thread, but i just want to ask when i removed my spark plugs, how come i can only see a hole at the end of both the trailing plug holes and not the leading ones?

is this normal?

Normal. Trailing plug holes in the face of the housing are tiny and the leading holes are full diameter. So when you look into the trailing plug holes you see the small hole in the housing face. You don't see that small hole in the leading plug holes 'cause the opening in the housing is essentially the same diameter as the plug hole.

subscribed

Just finished installing new plugs last night, only took two beers to finish the install. I'm using the RX7 platinum plugs with shims from mazsport.

Does seem to rev up with a little more authority from 5-9k. I'm now using the mazsport coils, plug wires, and fresh plugs.

Will try to get a dyno soon and see if it made a difference, my dyno on weak oem coils was 173whp

Thank you very much to the people who submitted to this great thread and the OP!

-Bill

Last dyno I ran, 194 to the wheels. Stock was 181.5. Did have a bout when the plugs were wearing and hit in the 170s. I have flywheel, intake, exhaust, pulley. I change my plugs now every 10k miles. Hope you have a good run.

ok, i cant my plugs off. i was using a 13/16s wrench and try with all my might (my brother tried too) and that thing was stuck.

any suggestions? im about ready to go to a local garage.

ok, i cant my plugs off. i was using a 13/16s wrench and try with all my might (my brother tried too) and that thing was stuck.

any suggestions? im about ready to go to a local garage.
Don't force them if they are frozen in there. You may end up stripping the threads in the housing and then you will need expert help to repair.

You can try something simple. May work, may not. I haven't tried it, but this is what I would do. Warm up the engine completely. Remove the plug wires. Put some ice in a plastic bag and wrap the bag around a plug for a minute or so. Then try to remove the plug. Repeat if it works. The concept is as follows: the rotor housing will expand as it heats up, the ice will shrink the plug threads as it cools down. You don't need much of a differential to make it work. I've used that technique successfully on other assemblies, but not the stuck-spark plug problem.

Remember, counterclockwise to remove, clockwise to install. If you do manage to get the plugs out and are planning to reuse them, clean up the threads and apply a little anti-seize compound on the threads before reinstalling. If installing new plugs, use anti-seize compound on the threads. Don't over to it, however.

yeah, i have anti-seize. unfortunately, porcelain is not the greatest conductor of heat.

:/

ok, i cant my plugs off. i was using a 13/16s wrench and try with all my might (my brother tried too) and that thing was stuck.

any suggestions? im about ready to go to a local garage.

it will be better to try to use a spark plug socket instead of just the wrench.

I've been there and I know how it end up. Go get urself a Socket and try again ;)

got myself the right socket, even tried the ice thing.

still no deal. they are frozen in there tighter than ... a lot of really really tight things...

im going to a mechanic. i hope they dont reverse the whole leading/trailing deal.

That shouldn't be a problem since the plugs have an "L" or "T" mark on them. And the coils have "L1", L2", "T1","T2" embossed on them were the plug wires connect. So you would connect a wire from L1 to the leading plug for rotor number 1, T1 to the trailing plug for rotor number 1, and so on.

I just replaced my plugs this weekend by myself. Super easy to do and I'm no MazdaManiac when it comes to this stuff. Now that I've done it, I can't believe the dealerships charge upwards of 400 for this. Took me about an hour and a half. 2 of my plugs were pretty brown on the ends. I believe that's bad from what I've read. It really made my car feel better. Very smooth etc.

Amen to that. Consider 80 or so for the plugs and about an hour or so for labor and it should be no more than 150 or so. That is what I would charge and, I would go to where the car is instead of bringing it to a dealer and get ripped off. Dealers dont seem to mind ripping you off these days. I was quoted over 300 for mine and told them thats ok, will do it myself and have put in 3 sets so far and car is running very well. It does make a difference with the new ones in.

Good stuff. I bought my 04' a few months ago and I encountered my first engine flood the other day after I washed my car. I guess I was unaware of the cold shutdown, but thanks to this forum, I feel I'm pretty well educated. Was able to get the car started after a few tries of the process listed in the manual. Just bought the NGKs last night to swap out the plugs and hopefully they arrive before the weekend so I can get crackin.

whoooo
just finished changing out my plugs and coils as part of my personal 60k maintenance. Wouldve gone aftermarket, but I've had pretty good luck with OEM coils... so yeah.

Didn't have my wheel lock keys with me.. actually couldn't find them.. so I did it with the wheel on. Actually wasn't that bad, still had a pretty clear reach. Just had to use two socket extensions and a dual hinged plug socket.
I must say.. my plugs were terribly fouled. The car was running pretty good, so I thought I'd just change it up at 60k (changed them once before via TSB) but after taking them out, I wish I had done it sooner.

Also did the coils by just lifting up the airbox without disconnecting the tube or any lines. My coils looked to be in pretty good shape, but I got a good deal on a OEM set.

Verdict? I now feel retarded. Over 30k or so, I never noticed how my car was degrading. About 60k on my car and idle is SO smoother now. At idle, I can barely hear the car running, and it's a lot more stable. Definitely pulls stronger, but more noticeably, smoother at all rpms. Kicking myself for not doing this earlier! Reminds me of when the car was new!

I've heard iridiums are not supposed to be cleaned due to the coating on the tip. Anyone confirm or deny this? Either way $80 to replace the plugs every 37K miles isn't bad.

This is half true, it has more to do with degradation of the electrode or in some cases I have seen the electrode so damaged it is un-useable from a nice cleaning session with a drill and wire wheel, if you know what you are doing then its usually ok, but I recommend just buying a new set. Also, I havent so far read anyone mentioning to be extremely careful with how much anti seize to use, seeing as it is a conductor, too much on the threads can get some in the combustion chamber and cause some initial misfiring, which can be really bad given the right condition.

Dont know why you are on my case about this. Super expert, in your own mind I guess. Deflooding is required when you dont let the car warm up properly. In the 30k miles I have had my car, not one time have I flooded my car. If you change your plugs out relatively often you will get better milage and keep better power numbers if you dyno it often. If you dont drive the car often or put many miles on it, 30k would be really pushing it as it would have a fair amount of build up on the end of the plugs. Believe what you want, I really dont care but, I do know what I see on my own car. I have talked to people that specialize in rotaries and, they say/do the same. If your car can get by on 35-50k miles, good for you, but I would rather change them more often just like Mazda says 7.5 on oil change. I change every 3000. Do what you want to but, my offer is cheaper than you will find anywhere unless you take labor out of the equation. I encourage people to do it themselves so they know it gets done right. The more people understand the rotary, the less skeptical they are about them.

Because this d-bag wants everything for free. If he is so noble to work for free call him up and see if he will spend his own gas and time to install some other guys spark plugs, I am sure you will get a prompt "no".

I think its nice of you to offer your time and know how to the uncapable for a minimal fee as far as car maintenance goes. I personally charge 60 and hour for mechanical work, 40 for audio work and 30/20 for close friends.

People need to realize that you cant expect hand outs, you want it done but dont know how to or want to do it, its going to cost something.

Keep it up I think your offer is more than fair compared to the stealer-ship alternative

I just would not want someone going to a dealer and getting ripped off. It is unreal what a dealer is charging just to replace plugs. Changing out plugs on an 8 is not that hard really but some people just dont want to fool with it and, I can help if that is the situation. I can come to their home/work and do it for them if they want. No extra for the driving. I have changed many plugs out on cars over the years and it is a shame that people still get a dealer to do that unless a complicated or hard to reach area. If you own a 3000gt or stealth, I feel for ya, or a fwd v8, the back ones are a little rough. I would like to learn how to truly work on one instead of just little things though, just have not had the time to go to school and do it. I have a hecktic life with my current job working on big machinery. The electrical system on the 8 is a bit picky and, if you dont keep on top of it, top end hp may suffer. Happy motoring and keep those 8s tip top :)

Been two years on these plugs, so got some new ones.

Newplugs, the redesigned coil packs and some Racing Beat wires......smooth like silk!

I always had a slight loss of power, a stumble around 7.5/8k, and thought it was natural - it had always been like that.

Now it's gone and revs strong right to redline! I'm a happy camper.


S

those don't look bad considering you went two years. HOw many miles did you put on in 2 years?

RB wires rock!

Getting ready to do mine this weekend! 60k of some pretty hard miles I cant wait to see what they look like! :Eyecrazy:

60k on stock plugs?! :scared:

I wanna see pics.

those don't look bad considering you went two years. HOw many miles did you put on in 2 years?

RB wires rock!

Don't look bad? Isnt brown bad - black good? Or other way around? I'm having a rough morning.

Don't look bad? Isnt brown bad - black good? Or other way around? I'm having a rough morning.

Other way around. Brown good, black bad.

They look amazing, considering the mileage! (I decline to provide figures, to protect the guilty! If you knew how far and long they went, I'd be asked to leave this forum....) And the reason there are only three? the other trailing plug was broken off at the insulator! Hadn't fired in a LONG time!

I premix real heavy, more than one ounce/gallon, so I was pleased to see the nice brown colour.

Can someone tell me which are the lead and which are the trailing spark plugs?

And thanks for the great pics!!!!

Thanks!

Simple way to remember:
Leading =lower
Trailing=top

The grammer may not be correct, but so what.

I see that Sparkplugs.com has Denso plugs for the 8. Does anyone know if these are any better that the NGKs? Are they worth a price premium of 75%?

Unless they can gap the plugs better than ngk, there is no benefit. Spark plugs just deliver the spark. The coils could make a difference if defective or burned. New vs new, there is no benefit unless the gap is off by either brand to the point where top end is affected. too wide a gap and takes more to make the jump, too short a gap and not much can go wrong really. .48 is stock but, if found to be larger, could hurt your coils in the long run cause will take more volts to make the jump and hence more heat to the coils on topend if above 5-6k depending on condition of the coil. Get all that? ;)

Got it. Thanks

Did this for the first time 2 weeks ago.

Took of the driver side wheel and had clear access to all 4 plugs... I didn't even have to go underneath the car. (1 jackstand)

Extension with a standard 13/16 spark plug socket got them all out easily. Took me 20 minutes to change all 4 spark plugs and wires this being my absolute first time.

EXTREMELY easy to do and learned a few things about my car in the process.

Only hand tool needed:

When I bought my '06 8, the glove box had four spark plugs in it. Are those replacements for the stock ones? And I had those spark plugs for awhile now, over two years without installing it, would they still work fine?

they might be the old version. got part #'s?
OR they could be from a completely different mazda that a tech or porter accidentally left in your car.

they might be the old version. got part #'s?
OR they could be from a completely different mazda that a tech or porter accidentally left in your car.

I don't have the parts with me because I'm at work right now. When I get a chance, I'll go grab it and post the part numbers. Thanks :lol:

they might be the old version. got part #'s?
OR they could be from a completely different mazda that a tech or porter accidentally left in your car.

Hey Jedi, the part numbers for the spark plugs are RE8B-T and RE7C-L and there are two of each kind. Are they for rx8s? Are they the old version?

I wanted to say thanks for all the guidance this thread provided. I changed out my plugs, wires, and coils today. I'm not very mechanically inclined so it took me 2 hours but I got it done and had fun doing it. Only 25k miles on my 04 but it was running like crap so I decided the car needed this... Man was I right. She runs very smooth now! Thanks RX8Club!

MKZTG
The next time you need to replace your plugs, you might want to try these guys, they are cheaper than dealer prices. http://www.sparkplugs.com/results_app.asp?productTypeID=1&AAIA=1416844
and they have the NGK plug update that Mazda required, you no for the trailing, or was it for the leading plugs.

BOB9995

Just changed my plugs at almost 60k miles. This set had almost 18k miles on them.

Just wanted to drop a line and say thanks for the DIY. It helped a lot

Is this really a risk? As in "Do you need to get them dripping with anti-seize and overthighten them like a madman and almost ask for it for it to happen" or as in "Anyone not an expert risks killing the seals simply by changing the plugs for the first time" ?

:sweatdrop


I'm going to change my plugs next week and have noticed a couple of posts similar to the above here. Is it necessary to index the plugs? Do they need to be shimmed so the reachis correct? Or do I just drop them in and torque to the specs?

Just recieved my plugs from Advanced Auto and wanted to verify that these are the current plugs for our car. I called Advanced Auto to confim this and they said it was correct. ...But, before I install these, I just need another confirmation from a forum member. These are the plugs sent:
The box says NGK Laser Iridium Premium(RE9B-T) and (RE7C-L)

Truly appreciate.

Just recieved my plugs from Advanced Auto and wanted to verify that these are the current plugs for our car. I called Advanced Auto to confim this and they said it was correct. ...But, before I install these, I just need another confirmation from a forum member. These are the plugs sent:
The box says NGK Laser Iridium Premium(RE9B-T) and (RE7C-L)

Truly appreciate.

yep. 7's in leading, 9s in trailing (that's also why the L and the T are there...)

yep. 7's in leading, 9s in trailing (that's also why the L and the T are there...)

RX8 Frontier:icon_tup:

After trying to clean and install some new plugs yesterday following the DIY, I noticed that the 2 trailing plugs (which need a wobble to be taken out) were going in the thread with an upper angle.

By that I mean that when I try to put the plug back in, the upper part of the plug is touching the end first, while there's a gap left at the bottom part of the spark.
It's somehow inclined tower to upper side.

I read that one person had the same kind of problem in this thread.

Any idea what could be done to solve that? What could be the consequence of having that?

It was the first time I removed the plugs myself, it was always done at Mazda before so I suspect they did that...

The 2 leadings sparks go in perfectly and firmly. Not the trailing ones.

i have that same problem. i was attempting a cleaning. so i started with the front rotor leading plug, i tried to install it and it just stopped only after going half way in. so i backed it out and noticed its threading wrong. just like the guy before you. so im taking it to a machine shop tomorrow and hopefully they can re tap it. wost case is a helicoil. in order to do that, they'll have to remove the left engine mount. im just glad it still runs but im only going to run it to get to the shop. im scred that since the plug isnt all the way in, its not going to ge tth eproper cooling effect from the block itself and may crack. and i do hear wat sounds like a very minor compression leak or rhythmic gas leak from that area. i cant feel anything around the plug though. and the idle seems fine and it revs up . but thats just dumb so im taking it to the machine shop monday.

Always use a dab of Never-Seize.

Always.

ALWAYS.

The steel will weld to the aluminum without it, always - I had my first rotary plug seize in 1976 and the need for anti-seize compound on the threads has been in the service manuals since back then.......


S

^Yup that stuff works great.

so uhh any solutions on spark plugs goin in crooked yet?

I did apply anti-seize to the spark thread. I guess it will make the removal process much more easier...

But still, before I install the 2 new sparks and cleaned the other 2, they were misfiring a lot. Now they don't, but Im still having a big big lack of power. It takes forever in any gear to get to 9K. No push at all.

I'm going to change the other 2 sparks so I ll have 4 brand new sparks installed but with the inclined trailing plugs, I believe that this is where the problem is coming from.

So can it be fixed? I have no clue how... and Im blaming mazda for that.

Actually they installed 2 coils last month along with a plug wire. When I was changing my plugs, I noticed that the wire was loose (on the spark end). Conclusion : I simply don't trust mazda dealers anymore. Specially when they tell me that changing 4 sparks is an 1h30 job.

So now, what should I do to get the trailing thread fixed? (get rid of the inclined angle)

Which plugs are normally replaced as part of that big TSB? I remember them only replacing one set.

I just replaced 3 of my plugs and the coils. The rear trailing plug would not come out no matter what. I was able to back it off a few threads, very painfully, and then it just stuck. It must be totally cross threaded. I cracked a 1/2" plug socket with my impact wrench trying to get it off.
The other trailing plug hole had slightly damaged threads as well, but came out and went in without too much trouble.

was this a problem from the dealer or did you guys cross thread it yourself? and "gtommy", were you driving this all this time around with your plug halfway in? or did you actually crank it down into the hole so it sealed?

okay well i got it to go back in finally, i had to align the plug at the exact same angle as the adjacent one. then put it in like a tap would. go in some back it out, look and put more antisieze and go in deeper next try. and low and behold, it went in nicely after a few turns. (note: i will not take responsibility if anyone tries this and it don't work how its supposed to)

was this a problem from the dealer or did you guys cross thread it yourself? and "gtommy", were you driving this all this time around with your plug halfway in? or did you actually crank it down into the hole so it sealed?

Before taking the 2 plugs out, I didnt check if they were well sealed. But I assume not since I always experienced a lack of power.

But I installed them back last week and I've been driving like that since then... Lack of power is still there but no misfiring yet... though I had a CEL this weekend for about an hour and this morning after a big storm first time I started the engine it died after 2 sec. Had to restart it and everything seems to be fine.

Im confident it's impacting the car performance and certainly other things like idle, vibration, cold start... But is there anything I can do to fix the threads?

Im confident it's impacting the car performance and certainly other things like idle, vibration, cold start... But is there anything I can do to fix the threads?

You can tap the threads, but I don't know if that's a job I'd want to do myself. If you don't have a tap set it'll still be cheaper than having it done, but I dunno if I'd want to risk getting filings in the combustion chamber.

I used one of these - http://www.shop.com/Wilmar_14_18MM_Spark_Plug_Hole_Chase-17009575-p!.shtml

It worked like a charm. I used a little bit of lube and worked the chase in and out. Every time It came out there was a little bit of metal on the lube. I wiped it off, re-lubed and continued until the hole was fully threaded.

Can chases be found at normal auto parts stores? Looks like it's just a less aggressive tap. Do they work on really buggered threads?
Does the 8 take an 18mm?

but I dunno if I'd want to risk getting filings in the combustion chamber.

+1 to that.

When the Cat/Compression recall happened, the dealer I took my 8 to x-threaded the rear Trailing plug. A turbo and almost 2 years later the same plug is still in there.

The Trailing plug has the smaller hole into the combustion chamber. That may reduce the risk of shaving getting into the chamber, but still don't feel comfortable re-tapping the threads.

Can't afford a rebuild just yet.

Can chases be found at normal auto parts stores? Looks like it's just a less aggressive tap. Do they work on really buggered threads?
Does the 8 take an 18mm?

Yeah I found mine at AutoZone I think. I don't know at what point a thread is too buggered to be chased, but it worked for me. I'm pretty sure our spark plug threads are 14mm.

I picked a chase up at Autozone last night (along with a good impact swivel and a deep impact socket set.) That plug should be coming out tomorrow. If 500 ft-lbs won't get it out... well, I guess it's part of the engine from now on..
The other trailing plug went in pretty tough, so I think I'll pull that one out and chase those threads as well.

This thread has been great. I just turned over 30K and am planning on replacing the plugs myself after being quoted between $200-300 at the dealership. My question is this - I have read throughout the thread people replacing plug wires and coils too. Can anyone educate me on how I can tell if I need to replace these items as well? Or like the plugs, is it generally just recommended at this stage fo the car's life? The car has been running good, I have just noticed it missing a bit while idiling. Thanks in advance for your help.

This thread has been great. I just turned over 30K and am planning on replacing the plugs myself after being quoted between $200-300 at the dealership. My question is this - I have read throughout the thread people replacing plug wires and coils too. Can anyone educate me on how I can tell if I need to replace these items as well? Or like the plugs, is it generally just recommended at this stage fo the car's life? The car has been running good, I have just noticed it missing a bit while idiling. Thanks in advance for your help.

pull your plugs. brown, coils are still probably okay. black is bad, corresponding coil is bad. if one coil is bad, the others are probably not too far behind. best to change them out all at once
as for wires, just do a visual inspection. probably not 100% necessary, but its not all that expensive so might as well do it while you're changing stuff there anyways.

Thanks cjkim, good info. I am going to change out plugs, wires and colis. I have already ordered the plugs through sparkplugs.com. Does anyone have sugestions of the best place(s) to buy the wires and coils?

does anyone know where to find good oem spark plugs for the 8, cuz i think mine is worn out , its at 96k but i doubt it if the dealership changed it when i bought it at 69k because they didnt even change the brakes , cause a month after i bought the car they were grinding i had to take it back , plus my tranny seems to be going up to 3rd gear and thats it , unless am driving with the pedal shifters then it goes up to 4 , any suggestions , its an 04 AT , plus is there a DIY FOR IGNITION COILS TOO

there's a group buy on plugs from mazmart right now

go to sparkplugs.com I have bought from them. I have not had any problems from them so far.

I purchased mine at sparkplugs.com as well. I found I could have saved a few bucks at fluid motor sports.

direct link to product:
http://www.fluidmotorsports.com/p-95...ccesories.aspx

If you do use sparkplugs.com, make sure you use cupon code "spccoupon" to get 10% off.

^ The link above didn't work for some reason. Here's the current one:

http://www.fluidmotorsports.com/p-95-engine-accesories.aspx

I found that Amazon.com has both plugs and is selling them cheaper than places listed above. They qualify for the free super saver shipping for orders over $25 since sold by Amazon direct. No sales tax for most states, including California. Make sure you're buying in from Amazon.com direct or you might get some outrageous shipping from 3rd party vendors selling on the site.

Grand total for me was $77.88 for two of each. However, I am hoping slow boat super saver is faster than the estimated ship date of March 30th and arrival April 6-10. Glad I'm not in a time crunch! *Update: It shipped today on 3/25. :)

$19.03 NGK RE7CL http://www.amazon.com/NGK-RE7CL-Laser-Platinum-Spark/dp/B000GZEU64/ref=pd_sim_auto_2
$19.91 NGK RE9BT http://www.amazon.com/NGK-RE9BT-Laser-Iridium-Spark/dp/B000AUP2VW/ref=pd_bxgy_auto_text_b

Wonder if the reviewer leaving the only review (5-star) on the NGK RE9BT page is a RX8club member. He gives good advice so he must be. :)

I found that Amazon.com has both plugs and is selling them cheaper than places listed above. They qualify for the free super saver shipping for orders over $25 since sold by Amazon direct. No sales tax for most states, including California. Make sure you're buying in from Amazon.com direct or you might get some outrageous shipping from 3rd party vendors selling on the site.

Grand total for me was $77.88 for two of each. However, I am hoping slow boat super saver is faster than the estimated ship date of March 30th and arrival April 6-10. Glad I'm not in a time crunch!

$19.03 NGK RE7CL (EDIT: see post above for fixed link)
$19.91 NGK RE9BT (EDIT: see post above for fixed link)

great find, thanks!

EDIT: links fixed, thanks!

great find, thanks!

btw your links don't work :P
Links are fixed - I hope! I'll let everyone know how they are when I get them. However, I think anyone who orders soon with a faster shipping method is going to beat my free super saver turtle express order.

Update: It shipped today on 3/25. Earlier as I was hoping!

Very nice DIY.

After removing the driver's side wheel, and the "rubber splash thingy" I replaced all four plugs straight in accessible from the wheel opening. You definitely need a socket extension with a 'wobble' adapter tho'.

The front plugs are now visible.

Got the Amazon spark plugs. Are they in gray/silver box and say "Laser Iridium" on them?

Great DIY - followed these instructions step by step and I was able to finish up in ~30 minutes!

Anyone try the Denso spark plugs from sparkplugs.com? $35 each. That's pretty steep.

I have, but I bought my RX-8 used with 39K on the clock so I don't have any experience with new NGKs. They are good, supposed to add .25 - .5 horses. I figure I will use only the best since this is one of my dream cars.

stick with NGK, you cant go wrong

Fantastic thread.

Seriously.

Lowest price I've seen on OEM spark plugs: ~ $66 for the set of 4 shipped from Amazon.com:

NGK RE7CL (http://www.amazon.com/NGK-RE7CL-Laser-Platinum-Spark/dp/B000GZEU64)

NGK RE9BT (http://www.amazon.com/NGK-RE9BT-Laser-Iridium-Spark/dp/B000AUP2VW/)

Remember to order 2 of each per installation and order from Amazon.com seller to get free shipping. Please post if you see a lower price.

GREAT find Rx8cited!!!

That is THE cheapest I've seen it..you are saving about $20! Sparkplugs.com sells them for roughly $21/piece plus s&h...bought a set ^_^

hey guys the thread was really helpful, thanks. i just did my plugs. only took about 45 minutes. $21/plug at a local parts store, wires are next.

My car was really rough starting. It also has a weird raspy type sound when I got on the gas thru 3-6k rpm.

So I replaced the plugs $84 (didn't fix the problem), then I did coils and wires $180 @ Atkins Rotary in Puyallup, wa. Problem fixed. i was able to change the coils by simply removing the airbox, which is pretty straight forward. and i have skinny arms, so i was able to avoid removing the FL wheel and just reaching deep into the engine and plugging the wires onto the plugs. including the plugs...maybe an hour or so for the plugs, wires, and coils...

Great thread and DIY...thx!

My car was running well, just some odd fluctuation at idle, drop and go back up and a little rough. But lots of power when driving normally.
Bought my plugs from vendor on here ($80us), did the change, idle seemed good, lots of power, but got the flashing CEL around 7500+rpm over and over. Slow down it would go off. Then one time it stayed on. So annoyed I reset the ECU via disconnect the battery. Redline it no more CEL and lots of power. However...when it's cold (start up) I get some crazy fluctuation in idle. When the idle slowed down to around 1500 rpm and wants to go down to 750-1000 (norm), it kinda sputters and kicks the rpms back up to 1750ish/2000ish. Does this a few times and for awhile. I have not waited for it to settle down. I go drive and then once more warmed up idle is pretty good.

Any ideas?

Oh and coils were replaced at the beginning of the summer.
Only thing I can think is wires, but they were replaced 1 1/2 or so years a go.

just to make sure before i do this leading is front and trailing is rear right?

when your under there, you can clearly see T for trailing and an L for leading

just to make sure before i do this leading is front and trailing is rear right?

I hope you were told better than that. L is for leading or Lower on both rotors. T is for trailing or top for both rotors. Best thing to do is one at a time and complete one before you do ANY thing to the others. Dont even take the wires off of another one til you get done with the one you are on. Its not hard really. Takes me about 15 mins or so after i get the wheel off.

Good suggestion to do one at a time; almost idiot proof (j/k). You can't miss the 'L' and 'T' cast into the motor housing (see the photo's earlier in the thread).

And don't forget the anti-seize paste. A single packet from Autozone (usually at the checkout counter) will last several changes.

A socket extension with a wobble joint really is helpful and taking the wheel off makes for a much easier job.

The wires run from the coils to the spark plugs correct?

ummmm.... yeah. The cables are all different lengths, so that helps run them properly, but again, best to do them one at a time.

The wires run from the coils to the spark plugs correct?

The wires run from the coils to the spark plugs correct?

The plug wires are different in that either the trailing or leading have a green stripe on it if they are stock. Just make sure you dont mix them up. You dont want your trailing plug firing before your leading and the leading fires 2 times during combustion. That would be very bad.

just for the information for people to remember easily...
T = TOP = Trailing ....remember T=Top, it's trailling (both Top)
L = LOWER = Leading ...remember L=Lower, it's leading (both bottom)

now, L1 and T1 .....front rotor (start from your front bumper)
L2 and T2 .....of course after front rotor.....(near the fire wall)

now the coil connection: L1 . T1 . L2 . T2 ....
the Mazda coil connection start from the front of the car 1, 2 , 3, 4...

you will notice that are 4 connections from mazda harness to coils, start from front (toward bumber) #1..and follow up with 2,3,4..

i give this information just incase people get messed up or need more ways to remember ...good luck
steven

I've already forgotten all that. ;)

Just match up what's already there (one at a time). Simple.

just for the information for people to remember easily...
T = TOP = Trailing ....remember T=Top, it's trailling (both Top)
L = LOWER = Leading ...remember L=Lower, it's leading (both bottom)

now, L1 and T1 .....front rotor (start from your front bumper)
L2 and T2 .....of course after front rotor.....(near the fire wall)

now the coil connection: L1 . T1 . L2 . T2 ....
the Mazda coil connection start from the front of the car 1, 2 , 3, 4...

you will notice that are 4 connections from mazda harness to coils, start from front (toward bumber) #1..and follow up with 2,3,4..

i give this information just incase people get messed up or need more ways to remember ...good luck
steven

so the oem ngk plugs are much better than the hks and greddy ngk plugs?

So i'm attempting to change my spark plugs myself for the first time. First 3 plugs came out easy. However the 4th plug, It is the top (trailing) plug behind the plastic splash flap will not come out. My spark plug socket does not fit in it very well and slips when I attempt to turn it, i think the sides may be a little bit stripped. It will catch if the socket is lined up perfectly with the plug, however I cannot hold it there and turn at the same time.

Its 3 hours later now, and my arms are pretty banged up. Any suggestions?

I'm using extensions however they wont go around the bend on the wheel arch very well.

This is why I use a 13/16 spark plug socket with a u-joint.
144940

As Jon cites a U-joint, or as I did earlier above and prefer in this application a "wobble" joint, is essential. Methinks a trip to Sears or Autozone is in your near future.



So i'm attempting to change my spark plugs myself for the first time. First 3 plugs came out easy. However the 4th plug, It is the top (trailing) plug behind the plastic splash flap will not come out. My spark plug socket does not fit in it very well and slips when I attempt to turn it, i think the sides may be a little bit stripped. It will catch if the socket is lined up perfectly with the plug, however I cannot hold it there and turn at the same time.

Its 3 hours later now, and my arms are pretty banged up. Any suggestions?

I'm using extensions however they wont go around the bend on the wheel arch very well.

So i'm attempting to change my spark plugs myself for the first time. First 3 plugs came out easy. However the 4th plug, It is the top (trailing) plug behind the plastic splash flap will not come out. My spark plug socket does not fit in it very well and slips when I attempt to turn it, i think the sides may be a little bit stripped. It will catch if the socket is lined up perfectly with the plug, however I cannot hold it there and turn at the same time.

Its 3 hours later now, and my arms are pretty banged up. Any suggestions?

I'm using extensions however they wont go around the bend on the wheel arch very well.

As with any job/project, correct tools make all the difference in the world when things dont want to go quite they way they should. Proper size and, in this case, a universal joint spark plug wrench of the correct size will work wonders. I would go to autozone or something of the sort and get the proper tools and concider it an investment for future sparkplug removals. DONT FORGET, put some antisieze on those threads.

First I'd like to say THANKS for the great DIY thread. After reading this I was able to easily change the spark plugs in my 8.

The reason I did it in the first place was because the car has seemed to lose a small amount of power over the 2 years I've had it and also has a bit of trouble starting. Nothing major but it takes several cranks. It goes Vabum vabum vabum vabum vabum VROOOOOM. If you say that out loud somewhat fast its exactly what it sounds like. Its at 54k miles now so I checked a plug, sure enough it was the nastiest plug I'd ever seen.

But after completing the job I really expected a bit more power out of it and better starting. But neither has changed. I just got done with it an hour ago and drove around for maybe 15 minutes, so I haven't tested it extensively or anything.

Should all this be expected? Or should I keep going and change the wires and coils as well? The wires looked to be in very good condition. I looked at both the coil connection and plug connection of all four cables and they're very silvery bright shinny looking.

Thx for any opinions or facts :beer:

I would change your coils and wires

I am forming the opinion that Coils should be changed at every other spark plug change.

And about 15,000 Miles is enough for the Spark Plugs, even though "Mazda" says you can go a lot further..yes, you can, but how efficient is the spark, from that how complete is your Fuel Igniting.

Much also depends on your type of driving and RPM's, even weather.

I changed my 'plugs at 20k miles and it made a noticeable improvement.

As we know, coils seem to be particularly susceptable to electrical degradation in the '8 and cables in any vehicle become electrically porous over time.

I'm going with the BHR coil/cable module near future.

Lowest price I've seen on OEM spark plugs: ~ $66 for the set of 4 shipped from Amazon.com:

NGK RE7CL (http://www.amazon.com/NGK-RE7CL-Laser-Platinum-Spark/dp/B000GZEU64)

NGK RE9BT (http://www.amazon.com/NGK-RE9BT-Laser-Iridium-Spark/dp/B000AUP2VW/)

Remember to order 2 of each per installation and order from Amazon.com seller to get free shipping. Please post if you see a lower price.

If you scroll down they also have a packaged deal that includes 1 leading, 1 trailing and a pack of NGK ZE81 spark plug wires for 59.00 so thats roughly 120$ for a set of plugs and wires.

did mine the other day really easy Thanks!

I am forming the opinion that Coils should be changed at every other spark plug change.

And about 15,000 Miles is enough for the Spark Plugs, even though "Mazda" says you can go a lot further..yes, you can, but how efficient is the spark, from that how complete is your Fuel Igniting.

Much also depends on your type of driving and RPM's, even weather.

Unless you are running lots of boost (even that is debatable) the stock coils are just fine. Its the connections you need to check. The plugs should be changed often, yes. The coils are good for a while. Make sure you have a good connection between the coil/wire, wire/plug. If the connection is loose, even just a little bit, will cause the coils to want to overheat and the spark will not be as consistant on top end. You should dyno your car often to see how it is performing and check the connection of the plug wires to the coils and sparkplug end too. I am going to find out what we use at work to make good connections to our annealers and let you all know so you can use it, its some kind of paste similar to silicon. Will keep you posted.

Wow- you guys aren't kidding about replacing the spark plugs often. I just changed the original plugs on my 04 RX8- with 33.5k miles. Wow- they are worn/fouled- though mine seem "oilier" than the OPs. The car runs so much better now.

If you scroll down they also have a packaged deal that includes 1 leading, 1 trailing and a pack of NGK ZE81 spark plug wires for 59.00 so thats roughly 120$ for a set of plugs and wires.


You only need one set of wires. So actual cost is $92 for 4 spark plugs and 1 wire set. Awesome deal. Wish Amazon sold the ignition coils too.

Autozone must have screwed up the order I made for the plugs because I ordered 2 leading and 2 trailing and received a box which contained 4 individually boxed leading plugs and another box with 4 individually boxed trailing plugs. 8 plugs total for for 84.99.

^ Yeah they messed that order up.
Nice x-mas gift

^ Yeah they messed that order up.
Nice x-mas gift

Yup...Merry Christmas to me! Maybe I should try my luck ordering some coils from there too. 2-for-1's on those would be really good.

bump

doing all 4 of mine tonight. i bought the car with approx 42.5k mi on it, now it has approx 57.5k mi. i have never changed the plugs, and to my knowledge they've never been changed in the past. so we could be dealing with 4 stock plugs with 57.5k mi on them. regardless, will post pics when done.

Very nicely explained tony.
I wanted to ask that will the car display CEL light if there is a foulty spark plug??

Hey, guys. I've read most of this thread and have a few questions. Is it recommended to change the ignition coils along with the wires and plugs? Which vendors currently offer the better prices on OEM parts? I'm sure I'll order the plugs from sparkplugs.com, so are the twenty-some dollar plugs sufficient, or are the racing class plugs recommended? I noticed the wireset from sparkplugs.com is much cheaper than finish line performance. Are they the same? Which vendors do you guys recommend for the coils? Finish Line Performance has them at thirty-five dollars each. I've heard people talking about one hundred dollar four-packs, but am not sure.

Also, using the wheel removal method, how long from start to finish is expected for someone with moderate mechanical skills and understanding? Don't wanna run out of daylight!

I needs plugs.
My car is the spark plug zombie...

Hey, guys. I've read most of this thread and have a few questions. Is it recommended to change the ignition coils along with the wires and plugs? Which vendors currently offer the better prices on OEM parts? I'm sure I'll order the plugs from sparkplugs.com, so are the twenty-some dollar plugs sufficient, or are the racing class plugs recommended? I noticed the wireset from sparkplugs.com is much cheaper than finish line performance. Are they the same? Which vendors do you guys recommend for the coils? Finish Line Performance has them at thirty-five dollars each. I've heard people talking about one hundred dollar four-packs, but am not sure.

Also, using the wheel removal method, how long from start to finish is expected for someone with moderate mechanical skills and understanding? Don't wanna run out of daylight!

there is a store on ebay selling NGK laser iridium plugs, NGK wires and 4 latest version coils for 375$. I bought it right away and installed myself. My baby feels fresh.

You can change plugs without changing the rest. Your wires and coils will probably last longer than your plugs but i wouldnt go more than 25k with them before i change

I have changed the plugs; miss-firing gone!!!
however, when it is on drive and idling, it vibrates the car, kinda funny noise I hear coming from the front of the 8.

Suggestions?

Are all the wires connected securely?

Ran into the same problem as kersh4u. First plug seems like its in there good. Even put a little cheater bar to get more leverage. Any one else find a solution to this problem?

Thanks

Can happen, just make sure you put an anti-seize grease on the new spark plugs threads before install...will make it much easier to remove next time, and don't over-tighten.

Use a bigger cheater bar is my suggestion. I think I needed an impact wrench to get one of mine out. Took all the threads from the block with it. Needed to helicoil mine. Hope yours isn't as bad.

My 8 has 67k miles on it, and i bought it 2 years ago with 48k... sure that a tune up had been done. i figured it was getting close to needing one again, but just to make sure i called my stealership. they looked through the records and found that the car has never had a tune up, and still has the stock OG plugs, wires, and coils... WOW. it runs fine except for a little wait on the starting (or maybe ive never really experienced what this car can do), but im going to replace it all this week and we'll see how bad it is...

Autozone must have screwed up the order I made for the plugs because I ordered 2 leading and 2 trailing and received a box which contained 4 individually boxed leading plugs and another box with 4 individually boxed trailing plugs. 8 plugs total for for 84.99.

SAME THING JUST HAPPENED TO ME!!!! it was great! the guy at the counter was like its your lucky day they sent you eight plugs! SO GOOD! 8 plugs for 85 bucks hell yeah

Just needing a little clarification. I ordered a new wire set, plug set, and a coil set. I understand the removal and installation of each, but I'm a little unsure of the average time? This week would be ideal to work on it, but it's going to get nasty by Thursday. When I get off work, it's almost dark out. Are we talking a half hour job? Hour? Three hour?

What are your experiences?

are the NGK plugs pre gaped?

Yes

All sparkplugs are gapped for their intended application, but a good idea to doublecheck them yourself.

Does anyone know of other working spark plug brands that I can use, its proving difficult to get NGK's in South Africa other than from the dealers and Im not willing to be bent over by them on pricing. I have heard that there are a Greddy version that can be used....anyone know the product code?

I have stumbled my way through most of the post's in this thread and still need to know what is the avg life span of our spark plugs mine are stock Mazda.:wallbash: