Hey all I have a question I was changing the spark plugs and one of the wholes was filled with oil what could it be from

 

What is the year of the car?

 

2000 gt

 

Is it a plug near the oil fill cap? Many times shops will spill oil when filling and it goes in there. I have seen this when intake gaskets go bad as well but usually not the case. I would pull the COP out again in a few days and see if there is oil in there again. If not then no worries. If there is then you need to look around at gaskets or suspect crack in head, which most likely is not the case