Hopefully, one of you guys know what is going on with this one...

My buddy has a 2003 Hemi and when the truck is first started, the oil pressure looks good. After about 10 minutes or so, it drops down very low. My mechanic friend put a mechanical pressure meter on it as well to confirm that the factory gauge is correct. It is.

So, the question is what could be causing this issue? Anyone have any ideas?

 

bump bump

 

FYI - it ended up being the pick up tube from the oil pump - there was some trash getting into the inlet filter.

 

That's what I was going to say. Did he recently switch to synthetic which started breaking up sludge or something? There shouldn't be any build-up in there if it was properly maintained.