M119 - oil on plugs

[AtlBenz]

1994 E420.

Check out this LARGE PICT. You're looking at the first three plujs from the passenger-side bank. Why are they covered in oil? What do I need to replace....valve cover gasket.

aside from that, how do I tell if I need new plugs? The car starts pretty heavy (cranks a bunch of times before it actually starts).