I hate to say it, but I'm with the other guys on this one, its probably the Rear oil gally gasket. the Oil pressure light is one of the few lights on the car that is almost always seriously bad news. because its intermittent it may just be the gasket is just starting to go

 

Mine was a suspension part. I get afraid to run Full Synthetic. Mine is a 2011 with only 175k on it.

 

Whats wrong with full synthetic?

 

Early synthetics would leak past seals that didn't leak with dino oil. Don't think that's a problem anymore.

 

Right. That hasn't been a problem for almost 20 years