Im having a similar problem.. Sounds like a supercharger!! not to jack the thread. but things to check when you hear this type of noise is the belt tensioner.. Anything else that is common to make this noise.. I would think anything with a bearing but that could be anything. Im probably going to post a video tomorrow morning

 

yeah my SAI is bad, and i have a bad pulley, either idler or tensioner. guess i will just have to pinpoint the noise. how hard are these to change? will i have to go into service position? any special tools required?

 

confirmed, tensioner pulley. is there a DIY on changing one of these

 

i wrote a small one here..

https://www.audiforums.com/forum/b5-...-160634/page2/

 

vgo did you change yours without taking the bumper off? I noticed the picture shows the engine but then one with the wrench with the bumper in. Im about to do this job. Fairly easy it looks like.

 

No, I didnt take the bumper off/put it in service position. The picture showing the front end off was just for reference purpose only.

Removing the electric fan, which i described really made it more possible to do this without removing the bumper off. Besides the confined space given, it was relatively easy to replace the tensioner pulley.

 

cool thanks, I am doing this job very soon.