Oil on spark plugs

[benkillin]

I went to change my spark plugs on my 1990 Toyota Camry delux 4
cylinder, and when I went to replace the spark plug, I saw quite a bit
of oil on the old plug. I checked each one, and they all had oil on them, but not as much as the first one.

I think this might be a piston ring or a valve
seal, what do you think is causing this and how much do you think it
will cost for a mechanic to fix it?

[88hawcam]

Is the oil on the electrodes of the plug,(The section inside the combustion chamber.) or is it towards the other end of the plugs(Where the plug boot goes over it)?

[Cyorke]

yeah need to know where the oil is located on the plug. If the plug tubes are leaking it iwll be on the outside where the boot goes over the plug. If it is on the electrode taht actually goes into the combustion chamber then it will be seals or rings.

[ToyotaGuy50]

If you know how to read spark plugs and you say oil on plug #1 I would assume that you took a compression test or leak down test and you would know whether it's valve seals or rings. (99.9% of the time it's valve seals very common)

If it is on the exterior of the plug your spark plug tube o-rings and/or valve gasket is leaking. (also very common)