Can you identify this Audi A4 part?
 

Heard a wooshing sound from my A4 instead of a whine from the turbo. Checked under the hood and found that this part had separated from its housing causing a serious air leak. New to turbos so I don't know what to search for. Thankshttp://forums.pelicanparts.com/uploa...1447632743.jpg

That is an issue. Boost leak vs air leak? Diverter valve area? Take a pic a foot back.

Assuming the whooshing sound is heard when you should be getting boost.

2002 Turbo Beetle/2003 Passat 1.8L Turbo. Will never have another. But I digress.

Ah, VW plastics.

Is that the top of the radiator? Yes, give us a little more context. It looks liek you may have to replace the y pipe and the tube that goes into it. Is there a slight crack at y point?

And regarding VW plastics, I am sorry, but I have to agree. I had 2 A4s 1998 and 2004, LOVED them. However, after 150k miles all the plastics start to dryrot and fail. I replaced about a dozen plastic peices on my car. None were extremely expensive but VERY time consuming to replace.

I am hoping my new volvo will get me past 200k... We shall see 180k to go!

It is some sort of one way check valve doohickey part of the pcv system

Venturi tube?

The top piece looks like a traditional PCV (positive crankcase ventilation) check-valve to me.
-It recirculates blowby and oil vapors in the case back into the intake to be burned up.
-It keeps the engine gaskets from pushing out when the rings are failing. When the leaking compression/ignition charge wants to pressure up the aluminum case just like a balloon.

Does that thing lead to the brake booster?
Or to a canister such as with an EVAP system?

^^^Winner! ^^^^ that is mostly correct -re-circulation...... valve - they fail early and often. Usually associated with CE on.........

Thanks for the feedback, guys. Discovered it is the suction jet pump, which apparently can affect the brakes! A new one is on the way from our host. It's a 2002 A4, so I plan to replace all the check valves soon too.