need help, again!

sometimes my car will start really rough or not at all, so i check the spark plug and i found oil on one of them, bought some spark plug, put it in, but after a couple of miles, i check it again and all four of them got dark. the one closest to the battery is the one with the oil on it. my car has 200k plus miles. can it be a seal leak or valve leak????? idk

 

is it leaking on the electrode or on the ouside of the plug?

 

maybe valve cover gaskets. its pretty normal for old motors.

 

My other guess is oil filler tube o-ring, its right by the front sparkplug hole on the driver's side

 

If not valves or gaskets the rings could be a problem as well. I would say do a compression test and see what you come up with. I you dont have the ability to or dont know how let someone on here know and im sure they could help you out.

 

when i remove the sparkplug, its all over it. not a lot though, enough to worry me.

 

perhaps try tightening it better? is the crush washer crushed?

 

yeah, thats what i want to do but i might just get a new used motor.