Changed plugs today, found something odd...
 

2004 Rx-8, 6-speed, 110k Chassis, 62k Engine. Catless (Mods in sig)

Quick and simple, changed plugs today. They had about 22k miles on them and been threw hell and back; had 2 coils fail on them, did a lot of "experimenting" with adjusting the vacuum for the MOP to increase oil consumption, several seafoams (maybe 5?), CobbAP OMP tables upped, 8oz 2-stroke per fill up, and about 80% city traffic.

Here is what I see when I removed them, my main concern is L1. (Pics left large for better view)

T1.
 

Trailing 1

L1
 

What is that green stuff? My worst nightmare????

Leading 1

T2
 

Trailing 2

L2
 

...

Leading 2

Any thoughts are appreciated.

80% city traffic

Not sure that really helps him at all. How does that explain his question of one plug looking the way it does out of 4 total?

From the looks of them I would say that you should stop picking your nose with spark plugs. That green bit looks like it is still gooey.

both leading plugs are caked with carbon ... one slightly more than the other, but that doesn't really say much. 5 Seafoams on the plugs? a bit overkill and can explain why the plugs look like crap. tons of city driving? looks like normal wear on an engine that isn't being driven hard.

Pic links removed. People can click on the thumbnails for the better view.

I would point to a combination of the many seafoams, increased omp, and using copious amounts of 2-stroke. You need to burn some air and fuel sometimes, too.

Well, my biggest fear is the green stuff is COOLANT... :sweatdrop

For my morning run I usually get to drive the snot out of the car. :lol:
But when I get off work I'm stuck in traffic the entire way home, rarely get over 4k rpms.
Visiting friends consist normally of a -3mile drive round trip, or just walking.

I "over oil" intentionally, I honestly think the factory maps for the MOP are garbage, combined with the lack of a center nozzle. When I bought this car it consumed 0.5qt per 2k miles. After messing around with it (Cleaning lines, nozzles, changing map) I got that rate up to 1qt per 1k miles avg, which is what I want. (It's what my 3 FC3S's consumed, never had a engine failure) and I premix on top of that like religion, with one tank of Lucas complete fuel system treatment prior to oil change. And then Seafoaming prior to every other oil change, to help get rid of the excess gunk from over oiling.

So... yeah... not too concerned about the over oiling... But can someone confirm the green crap is not coolant? I had made a thread awhile back stating I AM loosing coolant at about a rate of 4ozs for ever 4-6 months, and I can smell coolant near my overflow tank, which is brand new along with the cap.


(Sorry about the pics RIWWP :D:)


-Shawn

I didn't want to say coolant because when it is burnt on a plug it is usually a lighter color than that, and it might be the worst possible related problem. I would also generally think the coloring would be more spread out than just a single glob. My brain over-complicated it and thought the seafoam and large amounts of oil mixing may cause the color.

Agreed, when I see green, I think coolant. I'd recommend doing an oil test to see if you have a coolant seal failure in there.

I already have the "blackstone Kit" ;)

But since I just changed the oil (Old oil was already disposed of when I changed the plugs) Shouldn't I wait about 1k miles to do the test?

yes and no. Since you couldn't have changed the entire contents of the oil, if you have water in there it will still show up. Though if you don't have a pump of some sort, it could be difficult to get just what you need :)

I use my Pela Pump to pull samples, albeit, carefully.

Well, I was successful in removing 5.5qts of oil this time, just another one of my weird goals when I am in "maintenance mode". :lol:

I'm gonna give it 500 miles then remove the plugs and inspect them. Then at 1k miles do the test and change the oil again, you can never have enough fresh oil right? :) . And of course, continue to monitor my coolant levels closely.

The only thing I didn't do and I really wish I did was another compression test while I was doing the plugs. But L1 scared the crap out of me and I forgot all about it. :(

The plugs are all firing.....but they are quite oil fouled...so drive the snot out of it instead of mincing around town ;)

I wish I could but Kenner PD are some mean *******.
Example, in my last car (04 GrandAmGT), I was pulled over and kept on the side of the road for over an hour while they searched my car because when I took off from a light, I accelerated "aggressively" which didn't even involve tire noise or getting past 4k rpms, which is about 25mph when the speed limit was 35... They let me go, but my Popeye's fried chicken was Ice cold by then :(

if that was OUTSIDE the engine i'd agree, but i'm pretty sure INSIDE the engine coolant wouldn't look like that. why is it green? maybe the car ate some grass? st pattys day is coming up? its from mars!

The reason I think it's coolant is because I'm loosing coolant at a rate of about 4ozs per 4-6 months. Could be evaporation, but I'm gonna play it safe and get my oil tested.

ah-so! its very hard for coolant to leak into the oil, except for the freeze plug in the front iron, the coolant has to leak outside the engine and then back in to get into the oil. its not like its a dumb piston engine with a blown head gasket.

most common is the inner coolant seal failing, which leaks into the combustion chamber, the plugs should be clean, and you'd likely get a restart where it ran on one rotor for a short period, 10-30 seconds.

cooling system pressure test is the next step.

When my engine was leaking coolant into the combustion area, it would sputter for about 2 min. in the morning at first startup. Only in the morning and it would run fine the rest of the day.
Compare that with your experience.

That basically is my experience. :(

If I start it and only wait for the air pump to kick off before taking off, it runs pretty ruff (jerky)at low rpms, once it reaches about 100*f, it's smooth as silk. But it's always been like this since I bought it.
When I originally changed the coils/wires/plugs (oem set) the problem seemed to have vanish for a couple of days (and those plugs were just as bad as these), but then it came back. It got worse as time passed by on the plugs (I just kept blaming the plugs due to my "over oiling").
Since it's been cold lately, I been letting it warm up to 100*f (my normal start going spot when cold) and I notice nothing. No funny idle noises, no coolant smells in the exhaust while warming up, and there are always coolant smells near the overflow (I wash the engine bay every couple of months), but no signs of a leak. I even went as far as putting a Q-tip in the extended over flow tube and drove the crap out of it and it was dry. Also, no issues with cold start or hot starts, cranks right up every time.

The only problem I have with accepting that coolant is leaking into the engine is, how in 2 years and 22k miles it has never got worse (as far as coolant loss goes)?

Tomorrow morning it will still be pretty cold for my location (37*f) and I will force myself to take off after the air pump disengages and report my findings.


I'll see if one of my buds can pressure test the coolant for me on my next day off too.

Only 150 miles till I recheck the plugs.


Thanks for everyone's replies.
-Shawn


---- Not sure if this matters or not but just so you know, this engine is on the lower side of compression life. Tested twice now, but it's been about a year since the last test.

Sucking in bayou water?
Sorry...couldn't resist even though it's a stupid comment.