Didn't really know it was there, but the service writer suggested that after three valve cover gaskets, it wasn't unusual to find a cracked valve cover around the bolt holes. My idle quality had degraded recently and I was concerned the gasket was leaking oil into a spark plug hole. The new cover took care of everything.

Was it throwing any codes? Mine has stared idling a little rough, but it's not leaking oil into the spark plugs. I changed the VCG when I did the VANOS awhile ago.

No codes, but it was always worse when the engine was cold.