[s-cars] Water temperature sender.

[Rich Assarabowski]

Common problem, you have the classic symptoms.  It's difficult to
access, I used a 1 1/8" socket from an $8 plumber's socket set from Home
Depot (the ones they sell to remove faucets) and it was almost a perfect
fit.  Using a pair of Channel Locks will bugger up the brass and there's
no room to maneuver.

-- Rich A.
   '92 & '93 S4

>Replace Multifunction switch on water manifold. It is the guage sender
and is commonly avail for around $20.00. 
>It has four pin connector and is underneath intake manifold. This will
solve erratic temp guage 97-99 times out
>of a 100, and is a common failure/repair.