oily spark plugs

Sun Dec 14, 2008 10:32 pm

any ideas why 3 out of 6 of my plugs would be covered in oil, it was miss firing, cleaned em up and it all fine now. have to wait and see if it happens again. would it be the valves are not seated properly or does it sould like a crack somewhere

Wed Dec 17, 2008 1:23 pm

Wed Dec 17, 2008 2:43 pm

Valve stem oil seals... maybe..

Wed Dec 17, 2008 6:46 pm

rocker gasket possibly

Wed Dec 17, 2008 6:52 pm

do you mean the outside of the plugs were covered in crap or when you took the plugs out the end of the plug (electrode) was covered in oil?

Wed Dec 17, 2008 10:38 pm

The ends of the plugs where the electrodes are. It can't be a piston ring could it. It not letting out much smoke out the exhaust which prob rules that out. Strange, could it have anything to do with a valve

Wed Dec 17, 2008 11:08 pm

hmm now that I think of it valve stem seals have not been changed on this head, if they are knackered would oil drip into the combustion chamber, but surly that would affect compression, or would it just get burnt and straight out the exhause manifold.

Wed Dec 17, 2008 11:20 pm

do a compresion test,
which 3 plugs was it that were oily?

Thu Dec 18, 2008 10:36 am

Valve stem seals show blue smoke on startup from oil burning off which oozed in overnight. As they get worse, you get more oil coming in - up to the point when you get blue smoke pretty much all the time. Penny parts, but it is a head rebuild to replace them. You'll eventually fail your MOT on emissions so get in there well before it is due or start building up a replacement head you can swap nearer the time.