ShovelMan

LT1 Trans Am and I'm wondering why the hole is plugged up with a mini-filter thing.


Object blocking that hole looks like this http://www.dhresource.com/albu_23693...uad-pocket.jpg

leadfoot4

iTrader: (1)

A previous owner removed the fitting and hose, that connected to the side of the throttle body...

Wallj

iTrader: (1)

Pretty sure that's where you fill in oil.

Catmaigne

iTrader: (6)

It's for the PCV system. It plugs into the throttle body on the top left.

leadfoot4

iTrader: (1)

On second thought, the OP should have been a little more specific....there are two "holes" in the RH valve cover. One, the smaller one, for the PCV system, and the second, larger one, for the oil fill "stack".

SS RRR

iTrader: (2)

If it's in the small hole towards the back of the VC then it's originally for a breather tube which is then routed into the TB. LT1's are notorious for carrying oil vapors through that breather tube (neutral flow) into the TB and into the intake. Someone probably wanted to keep oil out of the intake and use that as an answer.
If it's a breather in the oil fill then it too is used in thinking it was an aide for the PCV system by supposedly helping the engine to rid itself of normal blow-by.