I was changing my spark plugs when i got to the last one. I noticed that the last one was drenched in oil (top, right one). What does this mean?

 

have u ever been over 100 mphs? i think thats your answer.

 

Where was the oil concentrated on the plug? Was it on the part that goes into the combustion chamber, or the part that sticks out of the chamber and plugs into the coil?

If it is not on the part that goes into the combustion chamber it is more likely one of the ring gaskets that go around the spark plug tubes. This was the case for me when I changed my plugs at 120k, I am now at a litte over 150K with no issues. Mine was not drenched, but did have some oil. If this is the issue, it is not that hard to fox since taking of the valve cover for the front does not involve taking off the intake plenum. I did not fix mine because plug with this issue was the one closest to the driver on the back. I may fix this when I change out the plugs again.

If the oil is inside the combustion chaber part, then there are bigger issues at hand.

 

check you spark plug tube seal which is in the valve cover had the same problem, they are $6 apiece you have 3 in the front and 3 in the rear you would have to remove the intake manifold

 

small black washers in the valve covers