hissing 8v

[seyles]

My 97 8v gti has started to make wierd hissing noises from behind the steering wheel. It started as a quiet hiss but is getting louder and is making the car noisy to drive.
Not too bad though. The hisses are very dependant on throttle opening (sounds like a carbed car after you've put a k+n pancake on). I've checked all the pipes into the throttle body and around the air filter box and can't hear a leak.
It sounds like it's coming from the servo, but again no loose pipes (that I can get to, talk about jammed in there!).

Anybody had this? Any ideas?

[SW VR6]

I have a similar problem on my 97 8v, although perhaps not quite as loud.  In my case, it started about a year ago, and nobody has ever been able to trace the cause of it.  

Like you say, it seems to come from behind the steering wheel (I thought maybe through the vents?) and it appears to be dependant on the throttle opening - can't detect it when it's idling.

Appreciate this doesn't really help, but in my case the noise has never got any worse and it certainly doesn't seem to cause any additional problems. I'd be interested to know if you manage to sort it out...