1993 S4 Jerk

["Robert T Rouleau" <RRouleau@dataradio.com>]

Riddle me this one oh Audi mavens of the List. My S4 with 5 spd has 
developed a new trick. At very cold temps, (-15F and below) AND within 
20 minutes of start up the car will give an almighty jerk 
occasionally.

This happens while I am drving at constant speed and (so far) onlyu 
when driving at more than 30 MPH. The jerk fels like I have stopped 
on the brakes. It is a sharp jolt and enough to spill your coffee big 
time. It matters not whether the car is constant throttle or, 
accelerating.  I'm suspicious about something binding in the 
driveline but there is not grinding of gears, squeal of bearings 
before or after the event. When it happens there is a big "clunk" 
sound and a sharp retardation of forward progress. It lasts only 
a second and then everything is as before. Dealer has no clue about 
this and it will *not* do it when a mechanic is present (suprise!).

Regards,

Bob