What are causes for oil on spark plugs in a Volkswagen Passat?

Well your in luck! you don't have much to worry about there. all it is is a seal that's needs to be replaced there i don't know if they sell them seperatley but what you want to do is go to the vw dealership and get one the kit with another seal well be around 50 bucks. how you get to it is take off the cover there and take the head off, its just a couple bolts there what you will see is the timing chain ect there and what you want is around the spark plugs there is this seal what it looks like is 4 rings going in a straight line, take that seal off and put a new one in, its that easy! have a good one and good luck!