I have 1989 Honda civic 160k miles, 4 cyl, one of the chamber of the sparkplugs have an oil pool, around 1/2 inch oil or so, but the other 3 chambers were clean, or only have a drop or oil on the spark plug tubes.
Is it the o-rings gone bad, or worn out valve cover gasket and grommets? or a plugged PCV valve?
I have replaced the valve cover gaskets just a year ago, and have only driven like about, 10k-12k miles, up to now.
I just want to know your take on this, should I just replace the PCV valve together with the valve cover gasket and see what happens? How would I know if it is the O-rings gone bad?
Update:EDIT:
The oil is visible over the engine cover and on the sparkplug caps, and into the well where you insert the spark plug wire....not inside the cylinder itself, sorry...
Answers & Comments
Verified answer
there is a rubber gasket (looks like a big "o" ring) between the valve cover and cyl. head on each spark plug. sounds like one is leaking. only cure is to replace them. clean the head and cover to remove all of the oil at the sealing surface and try a thin bead of "ultra copper" silicone on both sides of the "o" ring.
oil on the spark plugs means either you have bad valve seals or bad rings. Valve seals are fairly cheap and easy to replace. Bad rings requires a full rebuild of the motor. It is possible, not very likely, that the valve covers are not installed properly and the motor is sucking oil through the PVC system into the intake. (I've seen that once in 30+ years of working on cars) I would put the new plugs in it and see if you can start it. Once running look at the exhaust, blue/grey smoke indicated oil burning, white is coolant(very bad sign) black is over rich fuel mixture. If you gave alittle more info about the car, make, age and milage, I might be able to be less general in the information. For those saying a blown head gasket, it is not common to leak oil into the cylinders, it's usually coolant that leaks, or you get very rough running with compression leaking between the cylinders. Oil on the plugs usually indicates a high milage motor with wear on it.
If the oil is in the chamber and fouling the sparkplug then the oil seal ring on that cylinder is worn and letting oil through. Or are you saying the oil is visible on the outside of the cylinder around the sparkplug?