I have an issue where the air recirculate function is not working correctly. I have used both the manual and auto recirculate settings and the issue still occurs. I think the odors are coming in through the defrost vents. I have come to this conclusion based on the fact that in warm weather the odor issue is minimal/non-existent but in cold weather (when the defroster is most likely on) the issue occurs almost all the time. I took the car to the dealer for service and they could not find any problems. They said the outside vent door was closing properly. Does anyone have any ideas on what else I could have the dealer look at? I have a 2004 530i.

Thanks,

Steve

 

Hi Steve and welcome,

One should not use the AC recirculating function unless it's a must.

You may have some debris in the pipes, dead bugs or mold etc.

A change of the air filters and vent system cleaning is in order.


PS. I had an old mice nest under the plastic valve cover in my '99 320Ci.

 

It is definitely not debris in the pipes. The odors coming in are things such as diesel fumes, factory smells and other ambient outdoor odors.

Thanks,

Steve

 

How can a 530i get diesel fumes inside?

Yeah, well, OK.

You should just replace the air filters, if your car has any at all now.

There are two kinds of them, active and non active.

With your nose, get the more expensive active ones!
They are standard with the extended AC which I presume you don't have.

 

Simple, drive behind a diesel truck. Thanks for the idea.

 

Just look above