Leaking intake, AOS problems?

[zenocchio]

I remove the throttle body for a good clean and found the bank one intake manifold covered in grime. Not too bad but it got me interested. Bank two is clean, as well as inside the common manifold past the TB.

 

What would be the reason for that grime? Blow off from the aos?

 

[DBJoe996]

Not seeing much out of the ordinary here.  AOS breather hose goes to Bank 2.  That black and white thing is a vacuum check valve.  Check the plenum clamps and make sure they are squared up and tight.  Clean everything up and monitor.  The inside of the plenum looks good.  I always replace the TB O-ring when pulling the TB for cleaning.

[Ahsai]

Yes, blow by from AOS. Will be good to check the crankcase vacuum to verify the health of your AOS ~4" to 5" of water suction.