Back when I worked in the automotive industry as an engineer in climate control, this was a common complaint. Basically, stuff grows in your HVAC case. No way to avoid it. All cars do it, some worse than others based on how many biocides the manufacturers want to subject the car occupants to. Millions have been spent trying to stop the funk. No one has declared victory. Subaru seems to smell funkier than most.

The most a dealership will be able to do is spray cleaners in there to clean it out. If covered under warranty, probably not a bad idea.

 

In your experience is this type of stuff usually covered under warranty?
And I thought air will flow through the HVAC evaporator area even when AC is off...hence the old suggestion of turning off your AC few blocks away and just let the fan blow to dry it out, guess I could be wrong. That's what confused me when I get no smell at all from the fan alone, I thought if stuff is growing there, it would smell as long as the fan is on regardless of AC compressor on/off...

 

I used a home remedy of getting a can of Lysol antimicrobial air freshener, running the AC at full blast and spraying the Lysoln into the external air intake vents under the windshield. The theory is that the Lysol mist fills the AC and kills some of the mold and mildew growing on the evaporator coil.
I think it worked, but my biggest challenge was to get rid of the excessive air freshener smell. I picked what I thought the least obnoxious scent (something like "fresh laundry) - still it took a few days to air the car out completely. I'm sure youtube has some videos with the details....

 

Pretty much this, always kept a can of it on my tool box. I do it on my personally vehicles in spring and right before winter.

 

Here's the inexpensive DIY approach just to try something on your own; not sure if it will help:
Mold Control for HVAC Systems and Air Ducts - Ready to Use Aerosol 14o

The more expensive, professional car detailer approach, usually very effective and probably guaranteed by the shop that does it, is ozone treatment

 

You have to run A/C already? **** I thought it was warm here when we got to a high of 45 the other day haha. I doubt it would be covered under warranty unless you have a good dealer that works with you. Best to DIY or bring it to a detail shop to clean it out.

 

maybe the condensation drain hose is miss-routed or clogged - I'd think you could get that looked at under warranty. Demo the problem for the service writer before you leave so you don't get the call saying "We found no problem." If he claims he doesn't smell anything, either DIY or contact SOA?

 

There are commercial sprays available for this purpose too. I picked up a can at an auto parts store when I had this issue in a previous car. It seemed to take care of it for about two years, then I would have to give it another treatment.

 

I've had good luck with Ozium air sanitizer spray . Run AC spray into intake vents by windshield or remove cabin filter and spray into air box .

 

Just let the fresh air in without re-circ button on and it will dried out eventually. All car AC smell like that if you keep using re-circ all the time.

 

Mildew. Pretty sure I dropped that complaint once when at a dealer for a recall on my old Impreza. They found nothing wrong (evap draining properly), but went ahead and treated it with something that smelled quite nice when I got the car back.

 

I've never tried to do a warranty claim myself for smell nor do I know how successful one would be. Can't hurt to ask.

 

I dont have the issue on my Outback, but on a 35+ year old vehicle.....
Im going to use this to clean up the evaporator via the drain hose....

Apparently the condensate drain line (or condensate drain pan, if there is one) can get clogged and retain moisture and build mold in there....

 

I dont have the issue on my Outback, but on a 35+ year old vehicle.....
Im going to use this to clean up the evaporator via the drain hose....
Apparently the condensate drain line (or condensate drain pan, if there is one) can get clogged and retain moisture and build mold in there....

Exactly! I have used the home version of that spray on my central air system. Each spring I blast off the "A" frame below the furnace with the foamy stuff and let it sit for a few hours. then I spray-bottle in some distilled water to rinse it off. It leaves behind no residue on the coil but the water that comes off of the "A" frame looks nasty, brown and grungy. And I live in a home where there are no smokers, just a standard particulate air filter on the central air system but there is enough grunge in normal air that it builds up on the aluminum fins.

I bought a big can of the stuff at Home Depot.

Avoid using some chemicals because things like chlorine are very reactive to aluminum and others will dissolve the plastic in the ductwork. Also remember, that there is another filter mechanism in the car... its called your lungs... anything that you let circulate in the car is going to get scrubbed as it goes through your body. Try to not introduce nasty things in to that system.

 

Nope. This is not normal. I had a 2015 GMC Canyon that did this, and the dealer really didn't want to deal with it. Anyhow, I bought a can of Frigi-Fresh https://www.bgprod.com/catalog/climate-control/bg-frigi-fresh/. I think it was 10 bucks or so. It works if you follow the directions.

 

Have you looked at the cabin filter lately? It may be the source of the smell.

 

if I use the AC a lot - I'll turn it off, leave the fan on, and change over to fresh air... warming up the evaporator a bit helps reduce the amount of time condensation sits on the coils - found it will prevent the smell... I'll turn off the AC function about 1-3 minutes before I get where I'm going. Takes several cycles but the smell will go away. If its bad enough you may have to do what others have suggested.

 

The way to solve this is to take a can of Lysol and gently spray it in the air condition intake, which on most cars is located under the passenger and sometimes the driver's dashboard. Set the AC on medium high to high to get a good air flow going, make short 1 second bursts of spray. Do that about a half dozen to dozen times. The only downside is that for a few weeks, your car will smell like whatever scent Lysol you bought. I wish Lysol sold the regular scent in a can, instead of those linen and country smells. This trick works for regular AC units, and I use it at each hotel I go to, dumping a whole can in the AC, on the carpet, bed spread, bathroom, etc. Then I leave the room for the day, letting the AC run. You might want to pull out your air conditioner filter, if you just bought it, just so the stuff goes further down the duct work.


Update: originaltwotone stated that the air is drawn from the cowl. My post was implying that the air conditioner is set to recirculate, which is what I always have it set on, except for dehumidifying. I do this because I want to capture a good batch of air, not dealing with constant moisture intake, car fumes, etc. It also saves on the air filter replacement, since I'm not drawing in dust and dirt. Now, getting back, OTT brought up a good point, not only set the AC on recirculate to clean the interior ducts, but set it on outside, and spray the outside cowl intake to make sure all ducts are sprayed. It has been my experience that Lysol will kill mold smells for around 6 months or more.

 

The way top solve this is to take a can of Lysol and gently spray it in the air condition intake, which on most cars is located under the passenger and sometimes the driver's dashboard. Set the AC on medium high to high to get a good air flow going, make short 1 second bursts of spray. Do that about a half dozen to dozen times. The only downside is that for a few weeks, your car will smell like whatever scent Lysol you bought. I wish Lysol sold the regular scent in a can, instead of those linen and country smells. This trick works for regular AC units, and I use it at each hotel I go to, dumping a whole can in the AC, on the carpet, bed spread, bathroom, etc. Then I leave the room for the day, letting the AC run. You might want to pull out your air conditioner filter, if you just bought it, just so the stuff goes further down the duct work.

Actually it's outside in the cowl area.

 

There's mold in the air everyday. Just look at your weather report. Along with other pollens and dirt that get sucked up in to the air intake at the cowling, things that settle while the car is parked, etc., these things stick to the evaporator when it gets wet and the water lets it grow. The more humid it is outside, the more water the evaporator draws when the AC is running, even on recirculate. The air movement will move the debris around inside the air ducts.

If you want to kill the mold and rid yourself of the smell, a can of lysol sprayed in to the vents, HVAC main box where the cabin filter is and in to the cowling vents on regular basis will help control it. Also, a replacement cabin filter that is charcoal activated will help control the smell as well as help keep down the growth of the little buggers that is creating the smell.

You think Subaru is the worst? No. BMW thought it a good idea to put their cabin filters under the hood on top of the cowling where they pick up more road grime and moisture than any other design. Even when parked, if it's humid out, the filters soak up what's in the air a lot easier than if the filter were inside the car.

And on average, the cabin filter last about 15k miles, sometimes less depending on where you live and the weather conditions. So if your 18 Subaru is over 15k miles, that filter is probably dirty enough to need a change. And the more clogged a filter is, the easier it is for it to hold on to moisture, letting things grow in it. What breaks loose from the filter and blown in to the cabin will adhere to the carpet, especially those areas you don't think to vacuum and clean on a regular basis, like between the seat and center console, underneath the seat, door jams, etc.. Not to mention all the crevices in the dash paneling and behind it.

Once a year I take my car apart inside and clean it thoroughly. Takes all day and well worth it. Just regular maintenance as far as I'm concerned.

 

Or, to dry out the AC unit run the heat on high for about a minute right before you shut the car down.

 

I see my post got bumped again, so I might as well update.
The smell went away after about 10 days of running the AC on external circulation. The water being dripped were of a greenish color, definitely there were mildews growing...
But I didn't use any cleaning product, after about 10 days, the water became clear again, and the smell went away.

I also noticed the outback drips A LOT of water, compared to my other cars. There's always a huge puddle under it in my garage, that might explain why a winter of not using AC can have those growth, I guess it was never draining completely. But the good side is it apparently produces enough water to wash itself clean given some time lol.

 

There are many solutions, but they all require time and resources. The first thing a car service worker does is remove all dirt from the air conditioner heat exchanger. Also, work is done to remove all harmful bacteria and fungus, even in hard-to-reach places. To do this, you need to get close to the insides of the air conditioner, namely the evaporator. Sometimes this is a time-consuming task, as it is necessary to disassemble the dashboard completely. But in such situations, a specialist can disinfect with gas or special foam. This method is less effective but copes well with its task. The longer the problem of unpleasant odor is not eliminated, the sharper and more unpleasant the smell will be.

 

One method is to shut AC off with external air and run at high fan with high heat for a couple of minutes…. It dries out the moisture in the ducts. Btw…Toyotas can be pretty bad in the funk smell…

 

Hi all - apologies in advance for the necropost, but I'm reviving this post to (re)ask the question that seems to have gone unanswered - why don't the vents smell when the AC button is not engaged? Is there a vent door that block off the evap core when the AC is not "on"? If so, then isn't all the conventional wisdom about "drying out" the core before shutting down the car likely to be ineffective?

I ask because my (now 8+ year old) Outback's AC suddenly started having a weird smell recently (and I would not describe it as mold/mildew, FWIW), and it very clearly only happens when the AC/defog is engaged.

 

...my (now 8+ year old) Outback's AC suddenly started having a weird smell recently (and I would not describe it as mold/mildew, FWIW), and it very clearly only happens when the AC/defog is engaged.

My 07 Liberty (Legacy) has had a nasty smell from the AC for a couple of months, and I wouldn't describe it as moldy or musty either - it seems like more of a chemical smell.

Admittedly, I have my system on recirculate almost constantly because every other car is a damn diesel these days, and I can't stand sucking that crap... Might have to try running it on 'fresh' for a while.

But I've never smelled mold like that... I'm also getting the trickly sound behind the dash, and my AC compressor is a bit noisy, so maybe being in need of a re-gas has something to do with it? Might it be refrigerant I'm smelling?

 

 

Several people have already posted A/C cleaning products, but I'd figure I'd add this OEM kit: SOA868V9315 - Climate Control Cleaning - Subaru Parts Deals

Worked as well as I had planned. Had to remove the right front tire to get a better angle on the A/C drip hose, but would recommend