I Don't Think This Is Good...

[blind_elk]

Finally got my new Splitfire coilpacks from Slide tonight. While I was fitting them up, I thought I would check the spark plugs. The car has been running on "not all 6", so I thought it might have been a coil. Last time the engine ran like this, a piece of piston was playing pinball inside #2 chamber, and had punched the gap on the plug to nothing.

Anyway, found all plugs were generally nice and clean, 1 or 2 were a little black, but not bad. But #4 had a oil obviously coating the electrodes (these are Iridium plugs). Gave it a bit of a wipe down before re-installing it, because I don't have spares.

After all back together, fire the engine and engine runs smoothly.

But I'm concerned about the oil. What's your diagnosis?

[slothvr4]

oil on the spark plugs could mean ur rocker cover gasket is leaking

[SECURITY]

if its oil on the electrode, it could mean that you've got some nasty blow by caused by a f**ked piston/ring.

If it was light blow-by you'd see your electrode covered in a white chalky substance. but actual oil is a different story.

this could also mean that your PCV or breathers are blocked and is pushing oil into your combustion chamber.

im surprised you said 'a piece of piston was playing pinball inside #2 chamber' so casually. you didnt mention if you fixed this??

Edited January 10, 2008 by SECURITY

[blind_elk]

if its oil on the electrode, it could mean that you've got some nasty blow by caused by a f**ked piston/ring.

Not the diagnosis I was looking for. But it might be the excuse I need to give the cylinders a good hone. The engine was not really run-in correctly, and it burns oil a fair bit.

If it was light blow-by you'd see your electrode covered in a white chalky substance. but actual oil is a different story.

this could also mean that your PCV or breathers are blocked and is pushing oil into your combustion chamber.

Unlikely, since it's only in 1 cylinder.

im surprised you said 'a piece of piston was playing pinball inside #2 chamber' so casually. you didnt mention if you fixed this??

That was in the original RB20 - fixed it by fitting a new (RB20) engine.

[frozenwaffles]

how do you know its oil....?

if the cylinder is over fueling (ie leaky lower injector seal) then the plug will come out black and wet looking like oil but not actually oil... its just way too rich on that cylinder...

[blind_elk]

Yes, hadn't considered that possibility.

Was thinking of replacing injectors anyway - the little pintel things were all damaged. I'll have another look in the cooler weather.