Cooling fan not working

[JohnPaulBowden]

I have a year 2000 CLK 320 Avantgarde (Tip Auto). When in traffic the temperature gauge is rising dramatically. The cooling fan is not kicking in. Could somebody steer me in the right direction to diagnose the problem? Not currently in a position (financial) to be visiting a Mercedes dealer (or other), so any advise would be very much appreciated.

 

[television]

Your electric fan will not turn on under 100c and that is normal

 

[JohnPaulBowden]

CLK Cooling fan

Many thanks Malcolm. My worry is that during the time I have had the car, I'm fairly sure that the temerature has remained at 80c regardless of the driving conditions. It seems that all of a sudden the temperature has started to rise when in traffic or driving at higher revs. Is it normal for the temperature to fluctuate like this?

 

[television]

The thermostat range of delivery is about 87c, it could be sticky, they do not always last for ever.

The car will heat up in traffic due to reduced air flow through the rad, and more heat is dissipated driving at speed.

I would test it out after a drive and just leave the engine running to see if the fan does turn on after 100c, turn the air con on and it will speed things up

 

[JohnPaulBowden]

CLK Cooling fan

Thanks again, you're a superstar. I'll get it as hot as I can, and see if it comes on at 100c. Unfortunately aircon kippered, so can't help it along with that. Just to confirm that it is normal for the temperature to fluctuate?

 

[television]

Thanks again, you're a superstar. I'll get it as hot as I can, and see if it comes on at 100c. Unfortunately aircon kippered, so can't help it along with that. Just to confirm that it is normal for the temperature to fluctuate?

A slight erratic behavior could be down to the sender unit, in reality the temp is not changing that quickly, it cant due to the mass of the block.