[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: V8 - Running Temp High


Your radiator is simply a heat exchanger.  It's purpose is to remove excess
heat from the engine.  

The basic equation is: 

		Heat flow = constant * area * deltaT.

For any individual setup the constant and area are predetermined and will
not change.  If the only change is in ambient temperature then, in order
for the heat to be removed, the engine coolant temperature must rise.  

		DeltaT = coolant temp - ambient temp.  

If the ambient temp goes up then the coolant temp will also rise a more or
less equivalent amount.  This assumes that the thermostat is fully opened.

I realize there are other considerations such as rate of air flow through
the radiator, etc., but let's KISS.  (Keep It Simple, Stupid.)  Oops, a
funny, not a pejorative.  :-)

If your oil temp gauge isn't showing much temperature rise there are
several possible reasons.  One possiblity is that you haven't run the car
far enough or hard enough for the oil temperature to raise very much.  Does
the gauge not rise during a long drive at highway speeds?  If there is a
mechanical/electrical problem I'd put money on the oil temp sender rather
than the actual gauge.  This is (or should be - dunno about the V8) a
simple and fairly inexpensive fix AFAAG (As Far As Audis Go).

At 10:14 AM 7/31/99 -0400, patelr@squared.com wrote:
>My V8 is running around 105-110C at idle and about 90-100C when driving
>with the AC on.  Fluid is ok and the fans are running ok and the oil temp
>guage barely moves.  Mechanic suggested it could be the gauge.  Ambient
>temps in Toronto have been running in the 30's of late.   During normal
>summer temps mid to high 20's, engine temp is around 90C.
* Robert L. Myers  rmyers@inetone.net          Home 304-574-2372      *
* Rt. 4, Box 57,  Fayetteville, WV 25840 USA   WV tag Q SHIP          *
* '95 S6  Cashmere Grey - der Wunderwagen      ICQ 22170244           *
* http://www.cob-net.org/church/pvcob.htm  MediaRing Talk 304-574-1166*