Hello, I have a Mercedes C240, and there seems to be some sort of problem that I cannot diagnose. Even though I will have the heat on high in my car, when I slow the car down to a stop, for example stopping at a light, only cold air comes out of the vents... When I resume driving the heat begins pouring out of the vents once again, but will than once again become cold if the car stops. This doesn't only happen while the engine is warming up, even when driving for extended periods of time, and the engine fully warm it continues to happen. Cold air comes out of all vents, even from the lower vents for feet cold air comes out.

If someone could give me a few of the most likely catalysts of this problem it would be very much appreciated. I will be getting the work done at the dealership, although knowing what the problem is will save me money that I would have spent having the technicians at the dealership diagnose the problem.

Thanks in Advance[sm=feedback.gif]

 

What year and series is your car? If it is an older one and given the symptoms you describe, could they be due to fluctuating vacuum levels due to a leak in the overly complicated MB vacuum assisted air distribution system?

 

Oops. Just reread the title for you post. 2002. Hopefully they changed the air distribution system to something other than vacuum assist (like they did for the door locks on the W203).

 

Is this the only possibility? Are there any other things that may cause this problem by chance, and also, if this is the problem what is the expected costs of the repair?

 

Bump, any more suggestions before I let the experts at the dealership take a look at it?