Factory bov noise?
 

I have a 2000 a4 1.8t quattro n I hear a small air release wen I get on it from 1st to 2nd n its an automatic. It's all stock. My dv go bad?

You may be hearing the DV dumping surge air back into the system. If you're not seeing a CEL and the car pulls nicely after you get off it and jump back on, then your DV is working right.

What's CEL?

CEL = check engine light

the diverter valve should only come into play when you let off the accelerator.

yeah i hear that too anytime i shift gears around 0-5 psi, mine has a check engine light on, problem was system to lean or something like that idk, car runs just fine, sounds like a butterfly bov.... is there a way to make it louder? :D

If it's making noise, you need a new hooter valve.

Replace the diverter valve and the vacuum line to the DV. When you go to the dealer, ask for the TT 225 version of the DV, it's a lot cheaper than the "stock." Replacing the DV with a BOV or leaving it open will cause rich dumps between shifts, causing the check engine light to come on eventually.