Well, Im a bit confused here..i have two B5's, one quattro, the other is FWD (saves gas ) The quattro model, when i get it up to high RPM's like the 5-6k range you can clearly hear the turbo make a whistling noise, however my other audi, the FWD model, when its in the same RPM range, the turbo makes a loud sucking noise, no whistle as if you took a really fast,deep breath with your mouth. What is the correct noise the ko3 should make under heavy load? Im starting to think that the turbo in the quattro is going to give up on me soon

 

sounds like a vac leak. One of your vac lines probably came off. The only time you should hear air like that is from your intake if you have an aftermarket one. Otherwise all you should hear is a low whistling sound. Your quattro sounds fine, have your fwd checked for vac leaks. My quattro got vac leaks all the time because of my mods, the extra boost kept knocking off the oem lines, then I upgraded to the silicone lines.

 

Thanks for your help, I know a vacuum check valve near the air box is broken, im waiting for my replacement to come, and ill check for any additional leaks. I also forgot to mention, the FWD's DV broke and i had a good deal on a Forge splitter so i replaced it with that. Could that also be a factor? Once again, thanks.

 

your DV will not make an air sound. When the DV breaks its because the rubber diaphram inside tore so when you let off the gas it will honk. If your car is stock then don't get the splitter, there is no point, if you have it set to shoot out like a bov its not very loud. I had a forge 004 BOV on my chipped k04'd A4 and my cousin had one on his stock GTI and you could barely hear his. Mine was VERY loud. I would just get a billet DV from Evolution Motorsports. I used to have one, they work very well, recirculate the boost just like the factory DV and have no diaphram so they can't break. If it does they have a lifetime guarantee so you get a new one for free. I think they are like $130

 

My old DV already broke so i had to get a new one. A guy i know was parting his car out and sold me the splitter for $50. It works great but i agree, it could be louder. Im going to get the car chipped hopefully at the end of this month, we'll see how it works then.