[s-cars] Speaking of Steering

[Keith Franchetti]

Hi All-

My 1995.5 S6 Avant is starting to sing to me, or hum rather, on certain days, under certain conditions (which seem to be constantly evolving). Here's a typical such situation. I'm driving conservatively on a mildly winding Vermont route, say 40-50 mph. Each time there is a bend to the left, a certain amount of turning pressure on the wheel (and possibly the same degree of turn each time) will trigger this medium-high pitched humming that is not loud, but not easy to miss either.   Hum continues as long as the st. wheel maintains that approximate degree or turn.  Passengers will ask, "What's that?"  The sound resonates slightly through the steering wheel and the floor a bit too.  It feels like the frequency of the pump is somehow setting up a kind of resonance somehow.  I've wondered if a hose could be coming in contact with something it shouldn't and transmitting this resonating sound.  

Here is another way it manifests (occasionally--and the above is only occasionally too, by the way.  Lots of days there is nothing.  Temperature/humidity related?).  Turning into a parking space, when nearing the tightest turning radius at an, obviously, very slow speed.  Same sound.  Same frequency (so it does not seem to relate to engine/pump speed).  

Anybody ever experienced this, or have any ideas?  The mineral oil res. is at max. and does not seem to be moving (though there is a bit of weeping at one of the X-plugs on the pump, and near the end of the foam-covered hose that goes, I think, to the bomb).  

It's not really a major issue at the moment.  But obviously I'm hoping its not a symptom of a failing rack.  Failing pump would be a lot easier to deal with, but is that it???   Okay, thanks for any insight!

Keith Franchetti

95.5 S6 Avant
01 A6 2.7T
02 TT (for sale)