So when I start the car, sometimes I will hear a loud pop sound and it dies. When I check i saw my dip stick pop out and the vacuum hose connected to the BAC valve came off. It doesn't happen all the time, but when I hear the pop sound when im starting the car I know that the vacuum hose got disconnected again.

Car is a S4 N/A

 

do you have all your crankcase ports plugged off perhaps?

 

You're building pressure in the crank case for sure, not a good sign. Something is connected or disconnected improperly at a minimum.