I have recently noticed a strange musky smell coming from my AC. It only really happens if the temperature is set somewhere in the middle and is not blasting all cold or all heat. It smells like a mix between musk and bad BO.

Has anyone experienced this? If so, do you know that cause??

Thanks

 

Unfortunately, it happened to my brother's 01 C320. Here is a TSB on how to solve your problem:

SUBJECT:
Model 203.040/061/064/065/076/081/084/261/264/281/284/740/747/764
Model 209.365/375/376/465/475/476
Model 211.026/065/070/076/082/083/265/282/283

Air Conditioning Musty/Moldy Odor Complaints

Under certain environmental conditions, typically in a hot and humid climate, the vehicle may emit a musty/moldy odor from the air conditioning system. This will be particularly more noticeable when starting the vehicle and is due to the growth of micro-organisms from residual condensation typically on the evaporator and on the interior surface of the heater box.

If you receive customer reports in the above model vehicles regarding a musty/moldy odor from the air conditioning system, the Wynn's(R) AIRCOMATIC(TM) Ultrasonic A/C Cleaning System together with Wynn's(R) AIRCO-CLEAN(TM) Ultrasonic A/C Treatment is recommended. For the best, longest lasting results, apply according to the following procedure.
1. The evaporator must be dry before using the Wynn's(R) system. To assure this, drive for 30 minutes with the A/C switched off.

2. With SDS and a code number obtainable from TAC, set recirculation to unlimited".

3. Place the Wynn's(R) AIRCOMATIC(TM) Ultrasonic Cleaning System in the passenger footwell. Insert the hose in the luggage net and orient the end of the hose to insure the output from the device is sucked into the heater box.

4. Start engine, press recirculation button, select lowest blower speed and set the temperature(s) to minimum. The compressor must be running.

5. Install one container of wynn's(R) AIRCO-CLEAN(TM) in the Wynn's system.

6. Plug in the Wynn's system and check that it is running.

7. Close all doors and windows.

8. When the fog stops coming out of the Wynn's(R) system (after approximately 20 minutes), the dispersion process has been completed.

9. Switch engine off, turn off the Wynn's(R) system and leave windows and doors closed for approximately 1 hour.

10. Open doors and trunk lid/tailgate.

11. With SDS and the previously obtained code number, reset recirculation to limited".

12. Restart engine, switch on A/C, select the highest blower speed and set the temperature(s) to minimum.

13. Allow system to run for about 10 minutes. The cleaning process is now complete.

Check the "Reheat" setting, it should be set to "de-ice" on the 203 or 209 or anti-icing" on the 211.

To reduce the possibility for this complaint to reoccur, advise the owner to operate the blower at a higher speed, especially during humid conditions. For cars with a REST function, it can also help to use this feature during humid conditions when parking the car.

This treatment will last up to one year. More frequent treatment will not be covered under warranty.

The Wynn's(R) AIRCOMATIC(TM) Ultrasonic A/C Cleaning System together with Wynn's(R) AIRCO-CLEAN(TM) Ultrasonic A/C Treatment is available from the SSEP by calling 1-888-458-4040.

For the 211 only, in case of customer reports that the air conditioning system is emitting a musty/moldy odor from the vents within 3 months after using the Wynn's(R) product as described above, a new slanted heater box bottom which allows the condensation to drain better and a PU coated evaporator which inhibits mold entered production as of VIN A675828 and X171590. In this case, these parts can be installed in earlier cars. Be sure to thoroughly clean the inside of the heater box and make sure the drain tubes are not clogged before reassembling the system.

For the 203 and 209 only, in case of customer reports that the air conditioning system is emitting a musty/moldy odor from the vents within 3 months after using the Wynn's(R) product as described above, a Biocide coated evaporator which inhibits mold entered production as of VIN A731368 and F634900 for the 203 and F144091 and T042954 for the 209. In this case, this part can be installed in earlier cars. Be sure to thoroughly clean the inside of the heater box and make sure the drain tubes are not clogged before reassembling the system.

Good luck

 

You know, I had a musty smell occur to me about a month ago. Sometimes with the A/C off, the A/C on, Recirc on, Hot, Cold, it didn't matter. It wasn't consistent, it would come and go, and random across the temperature range. After about 10 days of this random on/off musk, it went away. I'm sure it was some mold or something, but how it cleared itself out idk....

 

I hate that smell. I've become accustomed to shutting off the AC a few minutes before I stop driving to prevent moisture from sitting in the evaporator housing. (shut off AC but leave fan on high)

Once the smell is there, it's hard to get rid of. One way is to take the evaporator out and clean it. (really hard to do). Another thing that may work is to wait for all the mold to die - which means don't let any moisture in for a month or longer. It's hard to not use the ac for that long though if it's hot out. Sometimes the mold will come back once it's damp again though.

Mike

 

I'm dealing with this bullsht now and have become a self proclaimed expert on the topic. Basically, because of the complexity of the heating/cooling systems associated with our vehicles, the problems with them have also become complex. Mold and such can affect different parts of the vents/evaporator to different degrees, making no single solution universal. There are too many places for spores, mold and dust to hide to make most solutions easy. For some, it may be a matter of changing the cabin air filter. Other times a long hot air blast will help. Commonly reccomended is a variety of products to spray into the intake above the battery or the vents above the footwell. As Mike said above, the evaporator may have to come out for a cleaning. I'd imagine in the worst cases, the vents would need to be replaced. I haven't completely solved my stench yet but spraying Lysol will buy you time if you have company.

 

It could be as simple as a clogged drain plug. Happened to my Vette after sitting for the winter.