For years I was chasing down an oil leak in my wife's 2008. Drove me NUTS. Dealer changed the timing cover under warranty, seemed to work for a while, then the leaks started again. For a LONG time it was just a drop or two here and there, nothing big. Then all of a sudden, it was leaking like crazy. I changed the tube for the oil fill, as it seemed to be leaking there. Seemed to slow but not stop. But when I changed it, I happened to have the engine running as a test while I put the cap back on and noticed air being pushed out of the cap. That's not right. So I checked further ... the PCV "valve" was clogged. It was thus building up so much pressure that it was pushing oil vapor past every gasket it could. So I changed the "valve" (really just a fitting with a hole in the shape of a PCV valve) and modified it with the larger holes as recommended somewhere here. Took a while to bet the oil cleaned off (I never knew how much oil the top cover could absorb), but I haven't seen a DROP on the garage floor since it finally cleaned up.
My advice - check your PCV valve first. You may not need a valve cover gasket changed.
