Re: 1987 300E Thermostat stuck open?

Tube Audio schrieb:
> Hi
> 
> 
> I have a funny feeling that my thermostat is stuck open and was
wondering if 
> there is any simple test to determine if it is open>
> 
> I just drove home about 35 miles doing 70 mph on the freeway.  The gauge

> never got above 60C, the weather here is 52F = 11C
> 
> 
> I would expect the gauge to go up to at least 80 or 90C
> 
> Does the 197 300E run this cold or is the thermostat stuck open and the
car 
> never heats up?

Switch off heating completely. Start the cold motor and let it run for 5 
minutes until gauge is beginning to show more than 40C.

If the radiator top feels like 40C the thermostat is open permanently. 
On the other hand if after a quarter hours driving the radiator is too 
hot to touch but your temp gauge shows 60C the gauge or the sensor is 
defective. May be even both.

To reach working temperature modern diesels need awfully long burning 
just the minimum fuel to move. But even in old times the MB six and mor 
always needed about one hour full throttle to reach equilibrium temp.

-- 

Roland Franzius