Hey folks, I have a '24 T with ~8K miles on it. It's been crazy hot lately (100F+) and after extended A/C use my car smells moldy or like a rotting cabbage.

I can change out the cabin air filter, maybe it's clogged? Any other suggestions?

Thanks!

 

Years ago when I worked at a Honda dealership, we would use BG Frigi-Fresh for customers with complaints like what you’re describing. You can get it on Amazon.

 

That's common all all A/C cars, there is a trick you can do to minimize that and its to turn off the A/C about 1 minute before car shut down. Leave the vent system running, just kill the A/C. That allows the ventilation system to get the moisture and condensation out of the vents with hot airflow.,

A

 

Mold has taken up residence on/in the Evaporator Coils of the Air Conditioning System.
Basically what you want/need to do is to kill the mold. Duh! There are a number of commercial products that can be purchased to accomplish this task. Pick one you think will smell nice. However, for far less money, 1.) Remove the HVAC Fresh Air Intake Filter (near the Battery on the passenger side of a 992). 2.) Spray (don't pour) a couple of bottles of Hydrogen Peroxide into the Fresh Air Intake (remember no Fresh Air Filter) with the Blower Motor on it's highest setting. The Air Conditioning need not be running and in fact it's better if the HVAC System isn't trying to cool the car. Set the Automatic Temperature Controls to a degree or two above the ambient temperature. Now turn the fan on to it's highest setting. You will need to do this manually. 3.) Spray the Hydrogen Peroxide into the HVAC Fresh Air Intake. An old Window Glass Spay Bottle is perfect. Not to worry, Hydrogen Peroxide harmless and almost all (if not all) of it will eventually come out the condensation drain. What isn't will be trapped by the in-car HVAC Filter. The condensation drain is under the car about a foot or two behind the passenger side Front Wheel. It's a small plastic tube.
You can also use laundry bleach to get rid of the mold, (same process) but it'll make the Air coming out of the A/C Ducts stink like bleach for awhile. Also,if any of the spray makes it through the HVAC System and into the car, bleach can do unpleasant things to the sort of stuff a car interior is made of.
When you're done, install new Fresh Air and In-Car Air Filters.
You should be good for the season and maybe longer, depending on where the car lives.

 

this is what I do!

 

I'm familiar and have turned off A/C for a few minutes prior to shutting down the car.

Interestingly, my LX570 doesn't suffer from this problem. Turning it off in the garage after having extensive A/C use leaves no smell. I guess I'm spoiled after my LX and expected newer cars to have "solved this problem."

 

My wife and I have intermittent problems with this on two Mercedes. A couple things we have found that help it in swampy Houston. Make sure to not leave the temp on “Lo” all the time. A 68-70 degree setting allows the compressor to cycle more often and allow the evaporator to dry a bit. Keeping the setting on “Lo” and recirculate allows the evaporator to get super chilled and continue to sweat well after the car is shut down. The recirculate also encourages already bacteria filled air to recirculate. While one needs “Lo” and recirculate occasionally on very hot days, I try to up the set point once it has runs a bit. Unfortunately Mercedes in our use has had more issues than my 911’s or the last two C8’s.

 

My wife's BMW has this problem, but my 992 absolutely does not do this... So it's not a 992 or Porsche specific problem. Seems bizarrely random.

 

My 981 had a similar issue, and workshop recommended me turning off the AC and running the heater at full blast for about 30 minutes. This worked for me and resolved the problem. If that doesn’t help, it might be a good idea to replace the filter.