hi i just buy a 2000 a4 i will like to now or identify is the diverter valve is bad or is in good condition . thanks

 

you will get compressor surge and will sound like a fluttering when you let off the gas. This is very bad for the turbo, its basically the air bouncing off the throttle body and trying to go back towards the turbo. This air can try to back spin the turbo causing major turbo damage. diverter valve releases the boost after the throttle body is closed.

You can also test the DV manually by taking it out first. Push the piston down with a socket while covering the vacuum nib with your finger. Remove the socket, and the piston should stay in the up position until you remove your finger. That's how i knew my OEM DV was failing.

This information came from using google search

Google

 

Thanks for your helpful response. Your diagnosis is pretty accurate. I will remove the part and check, if needed
I will replace it.

Thanks again for all your help.

 

A dv that's stuck open will also cause a boost leak problem.