Elec. fan runs when cold in A.M. 1990 300E?? - PeachParts Mercedes-Benz Forum

milhan · #1 08-12-2006, 11:32 AM

Every morning, when I start my car to go to work, the electric fan turns on high. The outside temp in the a.m is usually between 60-70 degrees F. So its not exactly desert tempertures. After driving about a mile, the fan will turn off. After work when the temps increase to 85 degrees, the fan doesnt turn on upon start up. I dont have the A/C, or the ECON switch on. Any idea why this is happening? I worry when it gets below freezing this will happen, and my car will never warm up. Thanks 1990 300E. 3.0

sixto · #2 08-12-2006, 06:49 PM

Do you see or hear fans? If you hear fans, you might instead be hearing the air pump warming up the catalytic converters.

Sixto
... stay tuned

milhan · #3 08-12-2006, 07:16 PM

This sound didnt happen last winter?? I will check this out, but Im pretty sure its the radiator fan. Didnt know about this air pump thing

sixto · #4 08-12-2006, 07:40 PM

Did you work on the clutch fan in the last year?

Sixto
... stay tuned

milhan · #5 08-12-2006, 08:55 PM

No I havent touched anything. This just started. Is there maybe a coolant pressure switch or something that could be bad?

brabus3.6 · #6 08-12-2006, 11:18 PM

From the sounds of it you have air-con but do you have the * switch or the EC switch? If you have the * switch ON or the EC switch OFF than it could be the fans coming on due to the AC being on and not being needed once the car has warmed and the viscous fan clutch has started locking. Just a possibility. If this is it than putting the * switch OFF or EC switch ON will prevent this noise.