Intermittent Temp gauge -- '94 90 Quattro

[Alan Lubow]

OK, I'm pretty sure I finally found the answer to this problem!  You may
recall my previous posts on this a few months ago.  I asked for advice from
the list and got a variety of answers.  Essentially I was told that this is
a fairly common problem, usually indicating a bad Multi-Function Temp Sensor
(MFTS).  Others mentioned that the problem could be anywhere in the wiring
from the sensor to the gauge.  One response mentioned that in his case, a
single screw holding the gauge to the back of the panel simply needed to be
tightened.  I started by changing out the MFTS.  Since the problem was
intermittent, this seemed to work at first.  But after a couple of days it
recurred.  I replaced the sensor with another and it worked for a couple of
weeks so I assumed that I must have gotten a defective new sensor.  But,
then the problem came back again.  Next I changed out the MFTS plug, by
cutting the four wires and I put another I'd rescued from the salvage yard
in it's place.  Once again thought I had the problem solved but after a
couple of weeks, same problem.

The gauge turned out to be easy to access.  Two screws to pull apart the
clamshell behind the steering wheel, then two more hidden at the base of the
instrument panel, which pulled out easily.  There was a single small
phillips head screw behind the temp gauge.  I touched it and immediately had
needle movement on the gauge!  It didn't seem loose, but somehow must have
been making a bad (intermittent) connection.  Tightened it up, and no more
problems since.  I'm crossing my fingers. . .

Thanks again to the Audi Fans for advice on this!

Alan