AC smell again 2002 W203 C320
 

I have had an onging problem with musty stink from my HVAC unit when I start up. I plan to have a B service (42,000miles) next week and have asked to have this problem fixed once and for all. The service advisor said that they will spray some frigy fresh in it and it will fix it for a while. When I nicely complained that this did not seem like a long term fix and I was tried of the problem he said all cars have this problem. Well my wifes Volvo does not have or has it ever had this problem. Seems like they are giving me the run around. Would one of you techs please tell me what I should do? Is this a common problem? Can the duct be changed? The car NEVER drips water on the round is this part of the problem? Do i need to get more demanding and ask them to get help from regional or MBUSA? Have any members had this problem and gotten it completly fixed? Thanks fore your help and time.

have them change your cabin air filter if it has gotten wet at any time it would give that musty smell to the whole car when the ac is on i believe most mercedes take to cabin air filters and if they do not have one readily available at the shop you can get one made by purolator from an autoparts store

You should see drips of water on the ground when the AC has been used. It sounds like the evaporator drain line is blocked. Search this forum for tips on how to unblock it or just tell the MB service advisor. The smell is not normal.
Dan

I have a 2003 W203 and this has never been an issue in our car. We have 42000 on ours. Also a good question is how often do you use your AC? We rarely use ours unless we really are hot, most of the time the windows are down and the roof open! But I have seen this posted on both MBWorld and MBKlasse forums in the past in the W203 section. Seems to be 2001 and 2002 W203's with the issue. I would check the drain lines and the Noise Encapsulation Pans under the car to see if there is any mold on the pans or the drains are clogged. I almost think this was down there, but it could also have been in the evaporator housing as well, I guess they had poor planning on the drains from the evaporator housing. Could be either.

MB issued a Technical Bulletin regarding this issue in June, 2005. This is a common complaint on several MB models. De-odorizing is the first step. If the problem persists, a specially coated evaporator ia available that sheds condensation faster, eliminating build-up. Of course they should check the basics first, but if an A/C drain were completely clogged you'd be getting water inside the vehicle. Keep us posted.