Intake gaskets replaced. Now squeal

1998 v6 3.8 upper and lower intake gaskets replaced last week by my cousin. Now when it warms up and you shut it off is squeals. Someone said it could be the gasket isn't seated right and it's sucking air from the crankcase? Any other ideas? It squeals after the engine is shut off for a few seconds.

The PCV valve should take care of the air movement. If it is stuck closed, then probably one of those new gaskets has a small leak, or has been forced to have a leak, because of the PCV. They are usually cheap, I would get a new one anyway.