Chosen Solution
So I went to do a tuneup on this Altima, oil was flooded inspark plug well, no smoke from exhaust.. or other tell tell signs of blown gasket
The most likely cause for this issue is a bad valve cover. The gaskets that seal the spark plug wells/tubes are part of the valve covers. It appears you would need to get a new valve cover altogether in order to replace the seals for the spark plug wells. I always get a new valve cover gasket unless it is fairly new already and clean the sealing surfaces well before reassembly. Looking at the cylinder heads online, the only other scenarios I can see or think of would be a cracked cylinder head or maybe a bad head gasket but it seems unlikely.
