Oil on spark plug thread

[roberco]

I replace the spark plugs on my 07 aveo and find that one of them is soaked with oil on the thread. There is no oil in the spark plug tube, though. Any help for diagnosing and fixing it would be appreciated.

[jayman]

I have the same thing. My dealer told me it was the valve cover gasket leaking.

[petrified.rabbit]

what do you mean by spark plug tube? it could be a drip of oil seeping to there from a valve cover gasket, or a spill filling, etc.

If the pug does not foul, the oil stays at capacity, and it doesnt happen more profusely i wouldnt worry about it too much.

[roberco]

I did compression tests (both wet and dry tests) and found that the cylinder where the spark plug has oil on the thread has very good compression, pretty much the same as the others. One thing that I don't understand, though, is that one of the dry cylinders (the one where plug has no oil on the thread) has 30% less compression than the rest for the dry compression test. The wet compression pressures are pretty much the same for all cylinders. This means that the piston rings aren't the root cause of my original problem. So, it's boiled down to which cylinder has a bad valve seal. The one with oil on the plug's thread or the one with 30% less compression. Man, I'm confused.

[petrified.rabbit]

or its fine and the cylinder "lost" pressure as you were continuously cranking it over without it running in between..

[Mark G]

Hi, I have the same problem with my 06. Pulled the plugs out and they were totally oil soaked. I think it might be more than a gasket, I'm thinking valve guides or seals. I just put new plugs in it and I will check it once a week, when they get soaked again I will take it to the dealer ( I bought an extended warrenty) I will report my findings later. This should not be happening at 45000 miles!!!!!!!!!

[mgwalker]

same happened with my 05.. we ripped the valve cover off and found the gasket wasnt sealing. so we put gasket back on as it was still good.. and siliconed it. fixed

[thehunterooo]

If there is oil on the plugs, it is the valve cover gasket, nothing more, nothing less (for the posts above mgwalke's) I do not see the problem, it is a cheap fix.

[byron84]

If there is oil on the plugs, it is the valve cover gasket, nothing more, nothing less (for the posts above mgwalke's) I do not see the problem, it is a cheap fix.

Yep my 04 just had the same thing.

[kashak]

I had the same problem, just need new valve cover gasket.