Air Conditioner Odor

[Radfahrer]

On one of the boards in the past year, someone gave a technique for cleaning the mold off the air conditioner coils to get rid of the musty smell when the AC comes on. Does anyone know the link?


Radfahrer '01 325 Ci Orient Blue

[fwt2]

I've had good luck on several cars, including my '01 325i, with the following steps.

Purchase a can of Lysol with a scent that you can tolerate. Loosely cover the interior H/AC vents on the dashboard with towels to catch the overspray. Open hood, remove interior air intake cover and microfilter. Clean the housing and filter, if necessary. Start engine, turn on AC and select the maximum blower speed. Spray half the can of Lysol directly into the air intake and run for several more minutes. Re-install the microfilter and cover. Repeat this procedure within a week if you still detect any odors. If this doesn't help, you'll need a BG Frigi-Cleen service, item (2) below.

For additional info, check out these links:
(1) http://www.equipment.org/JulyAug01.pdf,
specifically page 7 of the Adobe.pdf file.

(2) http://www.bgprod.com/autoair.html

[Radfahrer]

Thanks I'll check out the links

[bluebee]

[quote=Radfahrer;125003] get rid of the musty smell when the AC comes on. Does anyone know the link?

Deodorizing BMW IHKA and IHKR AC Systems (http://www.bmwtips.com/tipsntricks/AC/smell.htm)
http://www.bmwtips.com/tipsntricks/AC/smell.htm

Keep this design flaw in mind if you ever get Legionellosis (http://en.wikipedia.org/wiki/Legionellosis) from your BMW air conditioning system (http://www.athisa.es/english/legionelosis/legionelosis.html) as you'll be a very rich person, if you live long enough to sue BMW NA.

http://www.athisa.es/english/legionelosis/img/torrefrigeracion2.jpg

[Mech_Man]

I'm pretty familiar with the theory of this problem, having worked with HVAC systems, and living in the hot / humid south, so here's my thoughts.
This problem is going to be more common when it's very humid outside. (Obvious, but I thought it should be stated anyway).

To remove the odor: The above procedures all sound like they would help the immediate odor problem, but it should be remembered that none of them will keep the problem from re-occurring in the future.

To keep the order from happening next time. The only way to do that, is to try to minimize the amount of standing water left behind.
Anytime water from A/C condensation doesn't drain out and can form a pool that sits for a while, might be a place mold can grow and be a source for 'that' smell the next time you start the blower.

If this is a recurring problem, give this a try:
If it's humid enough a day that you think your A/C has generated water condensed out of the air, and there might be some standing inside the A/C core, then run the A/C fan for the last 5 minutes the car is running, with the compressor button TURNED OFF. This keeps the system from pulling more moisture from the air, generating more condensation.
The non-cooled air moving through the system will re-evaporate the moisture left inside the A/C core that was previously condensed.
Keep a window down or such, as the system will now be blowing air slightly MORE humid that outside air, and it needs to escape the cabin.
Experiment with the timing, as some very humid days might need more than 5 minutes.

Another thing is that if you shut off the outside air button, then the A/C will only have the moisture inside the cabin to de-humidify, and not a continually source of moist outside air.
If you ever have the odor problem, see if the car lets you close the outside air intake. (Some will re-open it as a default every time you start your car).

I typically keep mine shut, since I live in the hot humid south USA, and not cold dry northern Europe. Not having to A/C the hot & humid outside air portion also gives me at least 10% more A/C cooling capacity during full recirculation, so my cabin cools off that much faster from being in the sun.

[Dave 330i]

My American van AC does not smell like the BMVair's. Germans don't know squawk about AC.

[bluebee]

Combining yet contrasting the recommendations above, I come up with the following list of actions (http://www.bimmerfest.com/forums/showpost.php?p=3661472&postcount=81) to take. Is this a reasonable plan to avoid BMW Air Conditioner stink?

1. Once a month, turn the heat up to 90 and let it blow for 15 minutes.
2. Each day, turn the AC off five miles before you arrive at your destination.
3. Set the AC to 72 degrees, "Auto", "Snowflake", & "Circle without the A"
4. Drill a hole near the gas pedal side panel & spray disinfectant monthly
5. Unclog the drain hose for the AC condenser (under the center console)
6. Replace the "micro" filter (I don't see how this will help; do you?)

Is THAT what we recommend in order to avoid BMW AC stink?
1 & 2 --> dries up the water the bacteria, mold, & yeast need to thrive
3 --> reputedly supplies less water (but some say this step is useless (http://www.bmwtips.com/tipsntricks/AC/smell.htm))
4 --> kills the bacteria & yeast that are thriving on the condensate
5 --> reduces the amount of water available (if and only if the hose was clogged)
6 --> I don't see how replacing the micro filter will help at all (do you?)

Note that this article (http://www.bmwtips.com/tipsntricks/AC/smell.htm) says the problem is mainly due to the fact that you THINK you're controlling the outside versus inside air, but, if the AC compressor is on (i.e., snowflake lit), then you have absolutely no control no matter how you set the recirculation switch.

That one concept, if true, may be the true reason for all the confusion, as that would make the recirculation switch a non event, a red herring, a useless bone of contention.

Can it really be that half the people here (including me) don't have a clue whether or not the recirc button actually does ANYTHING when the AC snowflake is on?

(See supporting arguments here ... http://www.bmwtips.com/tipsntricks/AC/smell.htm )

http://www.bmwtips.com/tipsntricks/AC/Image7.jpg

[mdw750li]

:)I tried ozium per another members suggestion. worked okay for a couple of weeks. called the dealer and told them my issue and they covered it as goodwill. I bought the car during the winter so the problem did not appear until mid-Summer. Good luck.