W208 cooling fan running continuosly???????

[logs]

Hi, Can anyone advise if there is a seperate fan sensor to the temp switch on the engine of a 1998 320CLK that runs the cooling fan.
My fan is running non stop!.
Have tried disconnecting the temp switch on the front of the engine but this has no effect. All i can do is disconnect the fan and hope for no traffic jams, but really must find a permanent cure!

 

[Pookis Dad]

Fan Running On

Could be a fault with Air Con!

Does it have AC?

Failing that it could be the temp switch is knackd, Mercedes being clever and all would likely default to constant running to save the engine overheating.

 

[logs]

yes, it does have air con.
Forgot to mention that there is a warning about "fan operation" coming up on the dash as well.
Temp gauge seems to be working on dash ok, would think that if sender was faulty then the gauge would also read wrong.

 

[Pookis Dad]

To be honest I'm not 100% sure with Mercedes, but in most cars the temp sender is in the cylinder head so shouldn't be affected by the workings of the fan (in normal driving conditions unless car starts to overheat which would show on guage).

I had a problem with my Cherokee AC which made the fan kick in all the time.

I would suggest popping to the dealer or check the manual to see if the AC is in operation/faulty.

Unless the lads on here know better (which I rather think they will )

 

[Axcontrols]

My W210 035 has an aftermarket AirCon fitted by the dealer when the car was new.

In front of the engine cooling radiator is the A/C radiator in front of which is an electric cooling fan. This fan is not thermostat controlled.

Instead of a temperature/thermostat sensor - just in front of the fan is an AirFlow sensor. So, when the car is stationary the A/C fan runs all the time. When the car picks up speed and/or air is flowing through the radiator at a speed then the airflow sensor cuts the A/C fan.

As I said this is not the standard DB air con unit. It was fitted by the main dealer when the car was supplied new.

 

[television]

Put up the first 9 vin numbers, this could be a water problem

 

[star]

The engine fan could be running because of an engine management fault but more likely to be the fan control unit normally n/s inner wing under cover(not 100%sure its there)

 

[television]

The engine fan could be running because of an engine management fault but more likely to be the fan control unit normally n/s inner wing under cover(not 100%sure its there)

I know the C class and E can do that when water gets in to that box, if he puts up the Vin I will check

 

[logs]

Hi, thanks for all the feedback so far. The first digits of the vin are WDB2083652.

 

[jamesmc]

this kind of died a death... what was the result I wonder?