It's been a little cooler here the last few weeks so I've been running without the AC on, and sometimes even the heat. However, it was quite a bit warmer yesterday and I ended up turning the AC back on.

Wow! there was a terrible mildew smell coming from the air vents. The smell isn't there when the heat is on or if we just have fresh cool air, but every time we turn the AC on now we get that horrible smell.

Has anyone else experienced this with their R56? We're not using recirculation for either heat or AC so it seems like the air path into the cabin would be the same, so why do we get the smell with AC? Does the air get redirected into an area where water could have collected and mildewed?

Any ideas?

 

I had this in other cars and the advice was the same. Before you arrive at your destination, maybe 5 minutes or so, turn off your AC and just run the fan so as to dry off any moisture that might have accumulated somewhere before you stop the car. Its a habit for me so that's what I do with the MCS. Can't say if it will smell like mildew though if I tried just as how you're doing instead of how I'm used to turning off the AC a few minutes before stopping the car.

 

I have the same issue with my R53. The smell is like a bad case of dirty feet everytime I turn on the A/C on. I'm going to replace the cabin air filter and see if that works. I've already checked the evaporator drain and it works properly so the issue isn't stagnat water accumulating at the evaporator. The filter will be changed this weekend and I will report back with the results.

 

Replacing the cabin air filter will usually solve this problem.

 

Check and see if the Evaperator drain is blocked, sounds like it.. If it persists bring it back to the dealer to have the drain checked and cleaned.

 

What I don't get though is why I only get the smell with AC and not with heat or fresh air. If it was the cabin filter, wouldn't that affect all air entering the cabin?

 

Where do I find the evaporator drain?

 

I got that exact same smell at around 4000 miles. At 1st I got it when the weather turned cooler and would just run the fresh air. Then eventually I got the smell whether it was AC or fresh air. I haven't gotten around to changing the cabin filter but hope this will fix it. Will also check the evaporator drain as suggested here as soon as someone explains how to do this.

 

Dont know exactly where it is, but if you park your car after a run with the AC on, in you will see a little puddle of condensate water under the car when you park.trace this out and it will lead you to the little drain which comes from the AC evaporator housing. You will have to put the car up on ramps.

 

I replaced the cabin filter this weekend and.....the mildew smell is gone! The old filter was nasty

 

Stop eating White Castles in your car. That should help a lot.

Glad you got it unstunk.

 

it's all this da*n diet food....danger...danger