1997 e320 w210 auxilary aux fan wont stop running
 

Hi to all

I have a 1997 E320 has about 72k miles. My aux fan does not seem to stop running. It keeps running when the car is on. It never stops. The car does not get hot. The temp stays right underneath the 120 line. Could some1 please help. Is it a faulty temp sensor problem? what should i check for thanks

The aux fan on that & most newer Benzs are computer controlled! The A/C system relays info to the fuel computer & the fuel computer turn the fan to the desired speed. IF the system THINKS there is too much A/C system pressure OR that the engine is too hot THEN the fan will run all of the time!

MOST of the time a scanner with live data ability can find that problem quickly!

oh ok so your saying i should hook up a obd2 scanner and it will tell me the problem right. I suspect that the problem is at the water temp sensor since the fan only stays on at high speed. It just keeps running on real high speed and its annoying cause the fan makes so much noise on high speed. Is there any other way i can test the fan or the sensor?
thanks

With the engine temperature 'just under the 120 line', I would expect the fan to be running continuously. That's way too high an engine temperature. Check your thermostat, and rad.

oh no sorry correction its right below the 100 line not the 120. I just checked the car right now it seems fine but when the fan kicks in it doesnt stop. I dont know why. I just had a coolant flush about a month ago. The car doesnt heat up it stays cool even on idle at full stop. I will do another check today since it is like 91 degress outside. I just get paranoid cause the fan is so loud when it kicks in and doesnt shut off.

ok sorry people now i have a problem. My car temperature is rising and is going to 120. The car is definetly overheating. What could be the problem. i just got my coolant changed 1 month ago. Could it be the radiator or the thermostat. The water pump looks ok and is not leaking.
please help