Help: W203 C220CDI cooling fan issues

[dchantry]

Firstly, my apologies if this has been raised in a previous thread. I've had a look and can't see anything exactly the same.
I have a 2002 C220CDI with manual air conditioning. The car has been in an acident with front end damage, although it's been repaired. As a part of the repair the condensor and compressors were replaced.
I've had the a/c re-gassed and it seems to work OK in terms of blowing cold air, although I can't tell as it's quite hard this time of year as the outside temperature of the car is somewhat colder than the minimum setting. The system does however take a while to heat up.
One of the things I've noticed is the noise level from the coolant fan in the engine is very loud and I can hear it in the cabin and when outside it's actually noisier than the engine. I thought I was driving blue thunder
Tried some things when turning engine on and have found following.
A/C off completely. Fan on, but at low speed so not as noisy.
EC and blower on 6. Same as abov for about 30 seconds and then the fan changes to very loud.
Auto and EC blower 3. Can't really hear the fan. Turn Auto off and blower to 6, same. Press Auto back on and fan on low. 30 seconds later fan comes on high and loud.
Once the fan is on, even when I turn the a/c off, I don't seem to be able to turn the noisy fan off until ignition turned off.
I've been told system works OK, compresor is kicking in etc, but the fan is a lot louder than a friends car which is exactly the same.
Does anyone have ideas.

 

[marcos]

Are you sure it's not the diesel operated pre-heater that you can hear. It comes on when the weather is cold and sounds like a mini jet engine.

 

[dchantry]

It's definately the main fan behind the grill. I've tried the car next to my friends. When he turns the engine on his goes ice cold or boiling hot within seconds dependant on his temp settings in the car and there is no fan on for ages. When it comes on it's quite quiet.
My car neither get's ice cold or boiling hot and the fan is going full belt all the time.

 

[television]

its worth noting this as well on w 203 modules there is a service measure a coding change in the ezs/eis unit for the ac many systems have run low on gas or had a leak gas has been replaced and the pressure/temp sensor brings a fault up this fault cannot be erased even with star diagnosis you have to go into eis/ezs and change the pressure/temp sensor to inactive and the ac will work
There is another fault that puts the fan on all the time, I will look it up later

 

[television]

its worth noting this as well on w 203 modules there is a service measure a coding change in the ezs/eis unit for the ac many systems have run low on gas or had a leak gas has been replaced and the pressure/temp sensor brings a fault up this fault cannot be erased even with star diagnosis you have to go into eis/ezs and change the pressure/temp sensor to inactive and the ac will work
There is another fault that puts the fan on all the time, I will look it up later

I have found no reason for the fan, it could be to do with the above