My 2008 528i has had a stinky AC since I got it. The first time the dealer performed a deodorization with some kind of "fridgy-fresh" chemical. Worked for about a month. Then, the smell came back as bad as before. So, then they did a complete treatment with the ozone machine. For the next few weeks after that, the car had the most funky irritating smell. But, when that smell finally went away, I thought everything was OK. Here again, the smell comes back. Every time I turn on the car with the AC on, the nasty moldy odor is back for about 5-10 minutes.

I have tried leaving the recirc. button on AUTO all of the time, I have tried it set to always fresh air also. Doesn't matter. The dealer never charged me for any of those treatments, because as I see it, the AC system is in a car should correctly remove the condensation out of the system, so that moldy odors do NOT occur! I'm wondering if my condensation tubes are not draining properly. I think they are, because I've never noticed any water under the dash. It's hard to tell if they're draining correctly, because they drip onto that transmission tunnel pan, and the water just evaporates from there.

It sucks that the climate control system in a $50K car works like crap! Oh, and smells like crap! Well, it smells like pee to be exact!

 

i did the same, and it doesnt smell since.