RE: One Hot V8

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

> I was able to nurse the car back home to New York without much problem
> (interstate all the way). After taking the car to my regular mechanic
> (Greg Hayman @ Autofirme). he diagnosed the problem within 15 minutes.
> 
> As I understand it, the main cooling fan is operated on a clutch
> mechanism which receives a signal from a bimetallic strip. The hotter
> the car gets, the more the clutch is engaged. At approximately 105-110
> deg. C the clutch mechanism is supposed to be fully engaged with no
> slippage. We let the car idle and we were able to stop the fan
> (carefully). Therefore, the fan clutch was not fully engaging and was
> not cooling properly.

... you know, the funny thing is that a mechanic that specialized in other
marques might have nailed this one right off.  Not very many of the Audis
have fans that are connected to the engine directly.  

You didn't say anything about the operation of the electric auxiliary fan
though.  I'm concerned that this has failed as well, and may have
contributed to your overheating problem.  When I shut my car down hot I
often hear the fan running.  It is very noticeable as the computer controls
the fan speed, so you'll hear it run at high speed for a few seconds and
then a slower speed for a while longer.  

Steve Buchholz
San Jose, CA (USA)