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.

 

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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.

 

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.

:/

 

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!

 

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.

 

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!

 

60k on stock plugs?!

I wanna see pics.

 

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!