Oil on spark plugs?
 

Well, finnaly know xhy the miss fires. I just installed new set of plugs, run the car... car starts missing......I check the plugs...covered in oil already. What should I do?? How serious is this??

SERIOUS.

What year, miles?

1997 has 92k miles. It starts up fine, but has a miss..

Could it be the cam gaskets?

I was thinking piston rings. That would be a real chore to fix. Do you have blue smoke coming out of the tailpipe?

Nope. no smoke at all.. Just seams to have oil when I pulled the park plugs.

Hi HM1,

What does just seems to have oil when I pulled the plugs mean? Was there oil fouling the electrodes, which would indicate bad piston rings/cylinder bores (a bad thing)... or was the boot side of the plug covered in oil (above the threads) which indicates bad cam cover plug well seals (an easy fix).

Either one of these will cause misfiring.

It wasn't drenched in oil, just the plugs and the plug threads were a little wet(enough to cause a miss fire). There was some oil deep in that area, but not enough to cover the boots.

Ok, maybe it's me (it's been a long and brutal day and I'm not entirely here).

I'm still not clear on your description.


1) were the electrodes - the place that sparks - covered in oil?
- or -
2) was it the upper part of the spark plug body where the boot slips on and the metal part above the threads covered in oil?

I will take pics tomorrow, thanks for the help

92k could be piston rings, however I have found that valve guides generally wear out before the rings. First I'd run a compression test. Then do a leak down test. Hook up a compressor to the spark plug hole, put in a few psi. see if you can hear where the air coming out of. if you hear it leaking out the exhaust or the intake it's valves. If you hear it coming out of the dipstick tube, it's rings.

I went to do a coppreion check on it now, and dicided to start her up. She started right up, no problems. I even went for a drive, buttery smooth.. What could this be?

I had changed the oil few weeks ago with lightweight oil.. Could this be something to look into? Maybe some thicker oil for now, so it doesn't "seep" so much?

What did the compression check show? These cars gave issues with cylinder bore washing from fuel which causes low compression which I suppose could cause some blow by. However this usually causes a no start issue so I dunno

If you just switched to a different oil, synthetic, etc..valve cover gaskets and going back to a heavier weight oil should fix your problem. You're bound to keep getting oil in your plug wells until you do. The coil will eventually fail if you continue to let it misfire, and that's more expensive than just a plug.