So i got a 92 maxima se twin cam, coil on plug the whole works. So anyway i go to change my spark plugs and there is oil on one of the spark plugs. So i think either valve cover gasket or piston rings but the car doesn't hardly smoke. I guess i'm looking for some advice on what i could do.

 

How did you find out? After normal drive, plug swap? Does this oil appear immediately after short idle?

If all six fire, no smoke and/or oil consumption, that oily look on one of your plug threads (?) possibly was via leaking plug seal. In theory, each time plug is checked, one should renew that sealing spacer (me never done).

Compression tst will not do harm, more so if your going to keep/maintain and follow your new vehicle.

By swapping coilpacks you may follow if this problem 'moves' to next cylinder (if poor spark, as coilpacks tend to die 'after 100k').

I guess one leaking injector could flush some oil from cyl walls to be splashed around. Plug off injector ctrl wire from that cylinder, is there any change?