I've read a lot of post about potential causes of low oil pressure once the engine is up to temp and idling. It seems one of the possible culprits is a blown rear timing chain cover gasket. My question is if that gasket is the problem because it's blown/damaged, would there be visual evidence of oil leaking? I'm having abnormal low oil pressure readings on the dummy gauge at idle, but I also have no oil leaking from any area on the engine. It's clean as can be.