Re: 100CS & pig roasts & overheating

["Louis A. Mulieri" <lmulieri@zoo.uvm.edu>]

Dear Phil,
	I'm still cogitating on this problem with my Audi.  Without a/c 
on a warm day, >75 F, the temperature flucuates from 1/4+ to 1/2+ at 
which temperature the fan comes on and brings the temperature down.  Now 
my thinking is that below the temperature at which the fan comes on the 
thermostat is regulating the temperature to it's set point.  When the 
engine heat output exceeds the capacity of the radiator the thermostat 
stays open and the temperature is regulated by the set point of the 
radiator fan.  Question does this mean that the radiator heat dissapating 
capacity is low for the heat load or that I have a thermostat with too 
low a set point.
	With a/c under similar conditions the engine temperature is more 
constant and at about 1/4++ (I wish I had actual temperature calibration).
	Much appreciate your's and any other thoughts.
	Berthann Mulieri
	1988 5000 CSTQ

in the sun on a parking lot.  Meanwhile, the BMW is half as hot, and
> > the Toyota is much cooler.  Thus the joke, my Audi heats up enough to have a
> > pig roast under the hood. 
> 
> I'm tempted to say "that's normal".  Engines are designed to run at high 
> temperatures, and Audi intend the engine - once warm - to stay warm ready for 
> imminent use.  What's "hot" to you is "normal" for an engine - you'll see the 
> benefits in 100k or 200k miles, when the engine still runs without any apparent 
> signs of wear.
>  
> There _is_, however, one potential issue in the after-run fan.  This runs to 
> cool the radiator if it's _really_ hot, and sounds (in an enclosed garage) a 
> little like a Jumbo jet taxiing.  You should hear this at least occasionally, 
> and if you don't it usually means that the switch (on the rear of the radiator, 
> at the bottom) is either disconnected or defective.  On a five year old car, 

> there's a reasonable chance that this switch has gone.

	Mine does come on after stopping on a warm day; we haven't had 
any really hot weather yet. Berthann
> --
>  Phil Payne
>  phil@sievers.com
>  Committee Member, UK Audi [ur-]quattro Owners Club
>