How to remove moldy smell from AC?

[kazzax]

I have a 2007 bmw 328i, I’ve noticed recently that the AC smells moldy after I turn off the AC button. I leave the fans running to blow out any moisture before I shut the car off. I only seems to notice this smell when the AC is switched off and I don’t notice when the AC is running or when I use the heat. Does anyone have any recommendations to remove the moldy smell from the AC system. Or what the cause may be?

[cbpip]

BG FrigiClean and FrigiFresh.

[grannyknot]

There are lots of these kinds of products, this one is just the first of the search list.
https://www.lubegard.com/products/evap/

[ptpending]

this chemial cleaners have no long standing effect
the much better is to reach any detailing service or dealer, they have ozone generator with fan, it is put in closed salon for 45 mins with heater fan running and ozone kill all smell bacteria

[Mike_H_]

Originally Posted by ptpending

this chemial cleaners have no long standing effect
the much better is to reach any detailing service or dealer, they have ozone generator with fan, it is put in closed salon for 45 mins with heater fan running and ozone kill all smell bacteria

Ozone will do the trick, and you can buy a good ozone generator for less than $60 and perform the treatment as needed, when needed.

I buy, renovate and resell foreclosures and have been doing that for decades.

We have a few larger ozone generators and if we get a moldy house or one that has a lot of smoke or pet odors, after the strip out crew is done, I'll have them run ozone generators with the HVAC fan running for a day on a timer.

Because ozone isn't safe to breathe, after the ozone generator(s) are off for several hours, I'll have them retrieved and send in a framing crew can begin working.

Ozone generators work very well for deodorizing and pretty much killing residual mold / mildew spores. With cars, and houses, if the root cause of the mold isn't resolved the mold will return.

[ppointer]

Last time this happened to me, my evaporator needed to be replaced. Not cheap, but totally got rid of the stench. Car was a 2009 e91.

[RockCrusher]

Originally Posted by kazzax

I have a 2007 bmw 328i, I’ve noticed recently that the AC smells moldy after I turn off the AC button. I leave the fans running to blow out any moisture before I shut the car off. I only seems to notice this smell when the AC is switched off and I don’t notice when the AC is running or when I use the heat. Does anyone have any recommendations to remove the moldy smell from the AC system. Or what the cause may be?

The evaporator can acquire mold/mildew. If the catch tray drain under the evaporator is blocked this can also end up with mold/mildew.

In some cars there are water catch basins under the hood near the base of the windshield. These catch water that runs off the car's body panels and the basins have a drain that directs the water down.

The basins can also collect plant litter and this can block the drain. Stagnant water can collect and smell.

You can check for basins and address any standing water.

(Cars that I owned that had these basins as part of regular maintenance I would check for any trash and clean out the trash *before* any blockage occurred.)

If the evaporator has mold/mildew on it that can require the evaporator be cleaned. Likewise the catch basin under it.

But before you tear into the heater/AC system to access the evaporator a cabin air filter left too long in service can develop an off odor. Unless you know the cabin air filter has been replaced very recently I'd replace this first.

[ptpending]

the bmw e9x heater drain is leaking to gearbox body and then to gearbox cover
so to clean this drain you have to remove gearbox or be quite flexible