Valve Stem Seals or Valve Cover Gasket?

[NeDSM]

If i have oil on my spark plug and i do a compression test and it turns out fine, that means its not the piston rings right? so if thats the case how do i know if the problem is the valve cover gasket or if its the valve stem seals??

 

[steve]

If you have oil above the threads on the plugs then it's a valve cover gasket.

Steve

 

[latvianrkey]

what about oil on the threads? Compression test was 1-4 (185,180,185,180) So can I assume the rings are fine? #2 has a little bit of oil on the threads.

 

[steve]

what about oil on the threads?

You got me, Andy.
Which part of the threads? When I see oil on the threads I just assume the head threads are dirty unless it's only on the very bottom of them.

Steve

 

[latvianrkey]

i think there is oil getting into the combustion chamber for sure. The #2 plug is dirty (fouled) and does not look at all like the other three plugs. Would bad valve seals leak oil into the cylinder?

 

[pinknuggit]

valve stem seals are nowhere near relevant to what you're desribing. Get a new valve cover gasket.

 

[latvianrkey]

i hope it is only the spark plug valve cover gasket, but I fail to see how that would cause oil in the cylinder. Oil in the plug well maybe, but would it leak past the plug and into the cylinder? Thanks for any insight.

 

[steve]

Andy,

Oil can get sucked into the engine via the valves, valve guides, and seals It's not a problem I've had but what I remember the symptom is blue smoke after you have been idleing a bit but not under load. Try a google search on bad valve seals and see what you find.

I don't see a bad VC plug gasket causing oil fouling of the electrode. You have to be burning oil to do that.

Steve