Hi all! New to this forum and also new to owning a mercedes! Its great I have to say.... but only yesterday while sitting in traffic I noticed a problem 
The temperature gauge rises to about 80 when not moving. I got the car home and done some tests:
1) Started the car and left it idleing
2) Popped the bonnet to check all fans were working - yes they were...
3) Checked the water/coolant - all good and topped up
Attached to the engine is a big fan pointing towards the radiator and that was consistently going round and when I put the air fans on inside the car, the two fans in front of the radiator at the front of the car came on.
Now the weird thing is, if I set the heating to HOT inside the car and then turned on the air fans, the temperature gauge went right down to below middle. Once the internal air fans were turned off, the gauge slowly moved back to 80 again!
The car has had one owner and has got full mercedes service history and looks well kept but I can't help but think that this is a problem, that all cars temperature wise should sit level at all times, and not rise to one notch away from the HOT level if left idleing.
Has anyone got any advice or know what the problem maybe?
Kind regards,
Matt

The temperature gauge rises to about 80 when not moving. I got the car home and done some tests:
1) Started the car and left it idleing
2) Popped the bonnet to check all fans were working - yes they were...
3) Checked the water/coolant - all good and topped up
Attached to the engine is a big fan pointing towards the radiator and that was consistently going round and when I put the air fans on inside the car, the two fans in front of the radiator at the front of the car came on.
Now the weird thing is, if I set the heating to HOT inside the car and then turned on the air fans, the temperature gauge went right down to below middle. Once the internal air fans were turned off, the gauge slowly moved back to 80 again!
The car has had one owner and has got full mercedes service history and looks well kept but I can't help but think that this is a problem, that all cars temperature wise should sit level at all times, and not rise to one notch away from the HOT level if left idleing.
Has anyone got any advice or know what the problem maybe?
Kind regards,
Matt
