1995 E320 2-4-6 spark plug question.
 

Due to a strange vibration and following the advice from an old post here, I replaced the 2-4 and 6 spark plug connectors and the vibration calmed down a lot.

The concern, however, is that when I pulled the #4 connector I found a puddle of oil in the spark plug hole. The other holes were dry and the motor burns no oil...zip...nada...incredible for a motor with almost a quarter million miles. But that puddle is bothering me.

Anyone seen this before?

its probably the doghnuts that seal the rocker cover.Its probably time to replace gaskets.