what a bad spark plug looks like!
 

So, i just bought my 8 with 76,000 miles on it. And i took my car to the Mazda dealer for all the recall check up. They told me the small idle problem with car that requires changing the spark plugs, coils and wires. I told me it will cost about $300 for them to do it, so i said no thanks. I went online bought all the parts i need it with unbeatable price and did the whole thing myself yesterday. Here are some pics of the old spark plugs and coils.

http://i17.photobucket.com/albums/b8...9/DSC07761.jpg
i just bought the car 2 weeks ago, and i don't know if the last owner ever chang the damn thing, it looks pretty bad to me.

http://i17.photobucket.com/albums/b8...9/DSC07760.jpg

http://i17.photobucket.com/albums/b8...9/DSC07759.jpg

http://i17.photobucket.com/albums/b8...9/DSC07758.jpg
the coils didn't turn out too bad.

After i've changed all the parts, i went on a test drive and experienced no change. The idle is still there(only noticable when car is moving). So, i question if for it is normal for all the rx-8 owners with about 76,000 miles on their car. Also, i've heard the recall on the starter and battery? is it true?. My car doesn't start up right away. it has like a second or two delay. :uhh: any thoughts?

Those plugs are worn out bad...the ground electrode is half gone :)

Coils were likely OK..but you needed plugs about $20K miles ago

Reset the ECU and give it a few days to settle in

have not seen plugs that bad before

haha,,, me either:banghead:

Those have to be the original put in at the factory!!!

holy shit...that's bad. coils look like they got a little hot. i don't believe those are factory plugs...mine looked different.

funny how the car was still running strong. it didn't have any sign of loosing power at all.

im shock that ur car actually runs with only "little" idle problem.

Coils ~ Cant really tell by those white spot. cuz I had gone thru 4 sets of Coils in 45 K miles. 3 of them has "almost the same" kind of spot. but judging the way those plugs look, Im pretty sure the last owner never really cared about the car's maintenance.

I'll be taking good care of her now:)

Mine looked quite different as well. Mine had 4 ground electrodes. Since the dealer installed them I'm hoping they are the currect OE spark plugs.

if I remember correctly. OP's plugs were the old style plugs. Which SHOULD NOT BE there in the first place.

the newer plugs now has gaps between them to prevent flooding.

Aside from the ground electrodes being half-eaten, the plugs seem to actually have been firing ok -- the center insulators are a nice tan color.

Definitely past due for replacement though. These must be original plugs from a 2004 or early 2005?

You did get separate leading and trailing plugs for replacement?

Oh YES i did!

Then feast your eyes on these :)

http://www.classic-car-magazine.co.u...ide_chart.html

Aside from wear, the OP's plugs might show a bit of glazing but it's hard to tell. In any case, 76,000 miles puts to rest the notion that this car necessarily "eats plugs".

I seen that page like 10 million times.

for some reason, I always find that Mechanical Damage one pretty funny.

How often is everyone changing their plugs, anyway? Mine are stock, and have 23k miles. I changed out the coils and that made a decent performance difference, but haven't changed the plugs and wires yet. I'm thinking around 30k or next spring, whichever comes first..

Don't forget to dab a little anti-seize compound on the threads - you're lucky those even came out of the holes! Looks like the threads were just about ready to rust in there, longterm.

I changed at 20k - two insulators were cracked, changed again at 50k - one of the trailing plugs was snapped off at the metal/porcelain joint. I'd have to recommend no longer than 20k as a schedule.......


S

Wow, they're that prone to failure? Guess I should do it before winter hits. They're so hard to get to though, especially since I have large arms and hands. Oh well. Thanks.

Mine has a bad idle also, im an 04 with 72K. Ive ALWAYS had a less-than-smooth idle. Even after replacing coils, plugs, and wires. And it only got worse with intake screen removals and a typhoon intake.

If your truly worried about it, run a compression test but with a 1.3 liter, the idle isnt going to be V8 smooth.

Also, keep the fan off, thatll help with idle; my idle drops to 700 when I turn the AC on, then itll bump back to normal, then dip, then bump back to normal.

After a blip of the throttle to 6K, the idle will go down to a rough 700 for a split second than smooth itself out again at 800-900.

Its done this since day #1 at 19,000 miles and its still okay now at 72,000 so I wouldnt worry about it.

because rotary runs hotter than pistons. so yes plugs last a lot shorter.

And on a rotary, each plug experiences a combustion event once per RPM while on a piston engine it is once every other RPM. Combine that with a 9,000 rpm redline and that's a hostile work environment for RX-8 plugs!