Hello guys,
could not find anything similar to my problem online so here we go:
Audi a4 b5 97 1.8 ADR

One morning it started making this hissing sound(when I parked the day before everything was ok).

myvid:
https://drive.google.com/open?id=0B7...3V2TDBzaUdNR1E


if you see my video you can hear the sound fading a bit when I turn the wheel,
I already changed the pivot seal down there as I thought it might be letting air in, but it wasn't. I also checked the steering fluid - no foaming and no leaks,
the power steering seems not to have changed at all.
the groan has been there for years.

I would love to hear your opinion on what to check and what to work on first
thank you!
BR,
Karlis

 

I can barely hear the video at all.

 

My first guess was also power steering. The noises can change when you turn more or less as the pump works to move fluid around. My guess would be either the pump or some sort of issue/leak in the rack because it sounds like the sound is coming from down there

 

another thing I forgot to mention is that on a cold start there is no sound and it builds up -slowly takes about a minute