Hi,

well as I have posted in other topic my power issued at high speeds was solved after changing plugs at 28583 miles.

I think that my plugs seem overheated what do you think?

I know that overheated plugs can be caused by lean mixture but if this is the case what caused my lean mixture? My car is stock and there is no issue with fuel pump . Recently checked my compression and cat and they seem fine.

Do you think that lower octane fuel (cheap fuel or bad fuel) could have caused a lean mixture?

Do you think that late change of spark plugs at 28583 miles caused the trouble?


Thanks




Here you can see in detail the plugs
http://www.imageshack.gr/view.php?fi...8dh8uuc4nc.jpg

 

those look fine

Nice tan color. No missing chunks. No white melty parts. No black sh..stuff.

 

^ Are you sure that my plugs are not overheated?

 

typical wear and tear it LOOKS like... more info? how many miles on these plugs?

 

They dont look anything but normal. That tan color is just what you want. Dont just trust me. There are plenty of resources online that will give you a range of plug conditions via pics or you could show a mech.

Basically, for too hot, (or det) you would see obvious, ashy, whitish areas on the ceramic posts with a melty look or even bubbly. Or you might see pitted (or missing) terminals and posts.

 

Since the rotary burns oil, this is pretty much what you would expect plugs to look like that have seen some burnt oil. I agree with carbonRX8. Your plugs look pretty much the same as mine did when I changed them at around 30k miles.

 

Thanks guys,

My dealer told me that I may run too lean that is the reason of this appearance on the spark plugs. However I do not fully trust my dealer because he does not seem to know much for wankel engines and I have caught him telling me nonsense about some issues.

This is the main reason I wanted another opinion on the plugs appearance issue.

 

It looks like you have moisture leakage. Possibly from them not tightening the spark plugs enough.

or, Have you noticed that you have needed to add coolant every thousand miles or so?

 

28583 miles

Since I installed the new plugs car pulls very good at high revs and it was verified in a controlled drag race with a similar powered RX-8

 

yup.. just typical plug wear at almost 29k.

 

I have not noticed that I need to add coolant every thousand miles. I have added coolant 3-4 times in my car's life which is 28583 miles.
Well these plugs came with my car when it was new from the Mazda dealer.

 

not to hijack, but it is true that the oem sparks are the best to get? is there not a better aftermarket product?

 

I do not think so that they are best to get BUT since recommended from MAZDA you have no problem.

Anyway can you please post this question to another topic because it also interests me but I am more interested about my old spark plugs look.

Thanks

 

Is it possible that this kind of moisture is coming from bad fuel ? (fuel mixed with water)

 

Well there are some people that believe that the green marks on the sparks plugs indicate coolant in the combustion chamber.

Is anybody else that have seen green marks on spark plugs?

Any other photos ???

In case that INDEED there is COOLANT in the combustion chamber what would be the symptoms ????

 

Here are mine with 33K on them.

https://www.rx8club.com/showthread.p...20#post2153320

 

I guess that there is nobody with spark plugs and green marks on them ! Maybe I may have coolant is the combustion chamber although my car seems to have no issue till now.

 

Those looks fine.

 

what do you think for my plugs? Have you ever seen plugs with those green marks? Is it 100% coolant leak in the combustion chamber?

 

How many times you need to hear they are fine?

They have more deposits than OldRotor's - maybe buy just name brand gas, but otherwise normal. The brown deposit is a good indication that your mixture is right.

I would bet the green tint is an oxidation that appeared AFTER you took them out. Burnt coolant leaves no green, and if you burnt enough to leave visible deposits in BOTH rotors, you would have no coolant left.

Stop worrying, just change the next set a little sooner.

S

 

^ thanks for your response StealthTL.

Just for the history the first plugs were pull out at 28583 miles and the second set at 6250 miles. Both sets had green tint the very moment I pulled them out of the renesis.

So I worry that there might be leaking of coolant at the combustion chamber and that is the reason I scheduled a meeting with Dealer in order to pressurize the coolant system so a decrease of pressure might indicate the leakage.

In addition, I have never seen any other spark plugs that have green tint on them. Probably another person with this kind of appearance on his plugs will help by posting his experience here.

Anyway thank you all guys for your feedback on my problem.