I have a 2009 Fit with 9,000 miles on it. Ever since this past Spring I've noticed a mildew-y musty moldy smell coming out of the A/C. I asked the dealer to check it out while doing an oil change, and all they did was spray some car perfumy stuff. It masked the smell for a few days, but it came back. I complained to the dealer and now they're trying to make it sound like they were just "trying to save me money."

I shouldn't be having a moldy smell coming out of my A/C on a 1 1/2 year-old car, right? That should be covered by warranty shouldn't it? I don't accept all of the little tricks and tips offered by the service manager... there is a problem with the car and it needs to be fixed. Am I being unreasonable?

This is my 4th Honda... I've never had a problem like this.

 

All cars can have this happen. Which way do you leave the re-circulate/fresh switch most of the time?

Anyway once you get mold in the ac system, the first line of attack is to spray some mold killing stuff down the vents. It's cheap in terms of material and labor. The alternative is to take dash apart to get at everything and clean it out, which can get very expensive. A few other things to check are the drain for the ac to see if its clogged, and to only run fresh air.

 

It might be your Cabin Air Filter, which is located behind the glove box. I'd either replace it (you can find the filter way cheaper online) or tap it on something to clean it out a bit, lightly mist your favorite scent of frebreeze on it, let it air dry a bit and then put it back in the car.

I've noticed whenever I replaced my last C.A.F. roughly 6 weeks ago, the funky/moldy smell disappeared right away. That filter was pretty filthy after being in the car for roughly 10-15k miles (mind you, I kept the vents on fresh air and rarely used the A/C or fans at all).

Since then, I've been using the A/C and fans a lot more with the vents on fresh air the majority of the time. Only last week though, I've experimented with the re-circulation and did notice that the smell started to come back so I returned the slot to fresh air and the smell hasn't came back again yet.

 

Same thing here, 5k miles, car is about three months old.

 

Really? This is a natural occurrence for cars? In the winter I almost always keep it on fresh air to reduce windows fogging up. In summer (90's to 100 temp) I'll start on fresh, then convert to recirc. so that the cooled air will recycle and it won't have to keep cooling outside 100 degree air. Is that a possible problem?

Ok, I'll take some tips I guess. So far I've heard:

1. Run A/C but with hot air on full blast for a long burst - that could help kill stuff.

2. Use fresh air as much as possble. Maybe don't ever use recycled air?

Do I have any bargaining power with my dealer to do more than just spray something without paying for anything (warranty coverage)? Maybe after they do fix something I would then practice these voodoo tactics, although I still feel like we shouldn't have to do these things. I've never had mold build-up in my other cars in my 20 year driving career.

 

That's what does it. You're doing it exactly opposite of what you should do. Recycle to cool off a hot car then fresh to maintain. What happens with recycle is that the ac starts to condense the moisture in the air, which then allows for mold build up.

 

You have a point! How many people have had this problem in other vehicles?

I have a 98 Ford Windstar that has spent most of its life in FL with the AC on and no smell/mold?

Mold can be very dangerous!

Is this a common problem in vehicles or a design flaw by Honda? JIm 0311

 

I would check to see if the water is draining out of the car. If any water is staying in the car this will cause the smell. Water and carpet stink when warm. Just a thought.

 

Change your inner cabin filter. I use to live in Georgia and had this happen on my Toyota. I think the dealership can flush it with bleach to kill the mold. Humidity and rainy places can have this happen. Make sure there are not opened bottles of water in your car. Also, old food that you did not throw away in your car can make the mold smell. If your child left a banana or a sandwich under the seat sounds gross but it can happen.

 

this is not true..and here's why. The A/C condensor is getting cold which results in mositure being pulled from the air that is passing thru the condensor unit. Its just like a cold glass of water sitting in your kitchen...and water accumulates on the outside of the glass. Air that re-cycles in your car is lower in humidity since the humidity has been lowered for that air. If you pull in fresh air that is high in humidity, then more water will form on the condensor. The best way to prevent this is to ensure your drain line is clear, and turn off the A/C compressor just prior to arriving at destination. Run air (but no compressor) to dry condensor.

 

Malraux, thanks for your reply - I could see now how that might aggrevate the problem. I still don't think this should be happening (design flaw). The dealer did confirm that all water is draining from car properly. Also, the smell only occurs when the A/C is on... it's not just a smell in my car thus am certain it is coming from the A/C system. Doesn't occur when heat is on. Mold is particularly dangerous because in uppper 90 degree temps you point the vents right at your face on full blast.

 

Its about how much you cool the air. As the air cools, it can hold less moisture. You obviously won't get as cold of air on fresh as recycle but its air that isn't cooled to the dew point. Recycling the air gives the ac the chance to get all the water out.

That said, checking the drain is good too.

 

Malraux, so are you now agreeing with SpaceCoast? Should I use fresh air more or recycled air? When I'm nearing my desitnation will turn off A/C.

 

I disagree and think that you should use fresh. I do agree with him that drain plug clogging can also be a problem.

 

At the risk of adding confusion, what I find helps (at least when this occurred on other cars, hasn't happened on my Fit) was to be sure to leave the recirc/fresh-air lever on fresh-air while the car's not in use. This allows the evaporator coil to dry out better between uses. That and I try to avoid using recirc as much as possible, but with the current humidity and temps this is more often lately. By doing this I haven't had this issue on any car since living in Miami in the 80s.

++ change your cabin filter; this gets stinky after about a year in the south. It's an easy DIYer. Filter is less than $25.

 

I also read in another forum that if you spray Lysol somewhere outside near the windshield wipers that this will help kill mold / mildew when taken into the system. But does that mean just spray it in the air in front of the vents (not even sure where the vents are) or do they mean into/on the vents?

I will be using fresh air at almost all times now - even though it is humid outside, and will turn off A/C 1-2 min prior to shutting off car for the night. I'm gonna do the heater and A/C combo to heat away mold.

 

It's the intake vent right by the wipers. You want to get the spray down in the vents to get to where the water/mold is.

 

I have had this happen on other vehicles, and what I found that helps is to always keep the fan on to keep air moving through the system.

Whether you have the AC going or not, just keep the fan going and hopefully any moisture that forms in the vents will dry out befor mold can take hold.

 

Will it discolor or damage the plastic on the outside of the car if some of the Lysol gets on it? I imagine I will not be able to get a spray *into* the vent without spraying *onto* it. Thanks!

 

I think there are products out there specifically for auto-A/C mold. Here's one.

Also you might want to spray it lightly into the fan intake behind the glove-box after first removing the cabin filter.

Open the lower glove-box. Press in on the sides so the rubber stops allow the door to fall towards you. You'll see a "pyramid" structure that has an opening towards you. Move the fresh-air/recirculate lever and you can see how the mechanism works.

Remove the cabin filter. This is in a drawer just below the "pyramid" with tabs to allow you to remove it. Inspect for nastiness. Turn on the fan (car running) and lightly mist lysol or whatever into the intake (lever on recirculate). Don't soak it.

If you don't remove the cabin-air filter before doing this, you're just going to soak the filter with lysol or whatever along with whatever crap is in it and make mud.

Replace with a new filter and pop the glove box door back to its normal position.

Here's a link to buy a filter. (about 2/3 down the page).