I just finished changing out my head gaskets on my 93' 2.2L Legacy, put everything together, and I began starting it. It was struggling to turn over, so I ended up pulling the spark plugs only to find that the right plugs were coated in oil; however, the left were fine? Anyone have any ideas? I don't see how it could be the piston rings seeing that they were fine before? I'm clueless? Something to do with the valves?

The spark plug seals under the valve covers need to be replaced periodically, but it seems unlikely that both of them would go bad on the same side at the same time. It seals against the valve cover though, so maybe it's not seated just right? I would take off the valve cover and see what's going on under there. Easy first thing to check. Does the engine turn over by hand without issue?

 

ninja edit: Also is there oil all the way up on the inside of the spark plug boot thingy? Or just on the cylinder side of the spark plug?