EASY and FREE FIX: Get Rid of Moldy Musty Smells from Your Car Vent

get rid of moldy musty smells from car vent

This is the most effective “hack” I’ve ever discovered for air quality. And it’s in such an important arena of our life, where we all spend way too much time—our cars. Are you ready?

Well, first let me give you a quick background. You could have the cleanest, freshest-smelling, offgassed from manufacturing (new car smell), kept dry and mold-free, non-air-freshened with toxic chemicals vehicle, and still have this one problem. Mold from your car vents. You can clear this out by following this incredibly easy and free procedure every time you drive.

Riding the A/C Panel of Your Truck

Every summer, I ride the dickens out of my air conditioning control panel on my 1998 Ford F-150 pickup. I hawk the settings using two dials, FAN SPEED & AIR FLOW (COMPRESSOR). I do it with panache and deep concentration. This is all in an effort to keep out the nastiest offenders while still maintaining as fresh air as humanly possible in the cabin of my truck amid the toxic wastelands of our modern landscape. From the pesticide-riddled rural side roads to the exhaust-covered highways, with some nasty city smog to dodge once in awhile, driving involves never-ending strategic warfare against pollutants, coupled with a seductive dance to entice some good ol’ fresh air.


And I do a great job at it, until about May-June when things start to get humid. I live in Maryland, so it can get pretty humid, but not as bad as some of the Southern states on the East Coast. In the heat and humidity, the air compressor in the A/C tends to build condensation pretty easily. You can usually find a puddle on the ground under my truck where the A/C has dripped. That’s a good sign that you’re getting moisture build-up in your car vent.

With all of the thunderstorms in the early summer, generally the smell gets a lot worse. For awhile, I thought the rain was leaking into the cowling (what protects rain from getting into your air filter from the top of your hood), but that’s virtually impossible. Really it was all about air compression leading to condensation that builds up on the fan in the vent of your car.

What Didn’t Work

I started to look for answers on the Internet, which can lead you down some blind alleys. Yes, Google doesn’t have the answers all the time. A lot of sources like to blame this musty smell on the age of the vehicle. My Dad even theorized that there is a “planned obsolescence” built into the vehicle’s design to entice you into buying a new car. (Ironic for him to voice a conspiracy theory like this, because he thinks all of the Alex Jones stuff I talk about is absolutely insane.)

Having a truck from 1998, I believed that this was very unlikely, because I probably would have noticed before now. I believe it was just my sensitivity to mold (living with mold overgrowth in my home and in my HVAC), combined with an abnormally humid and rainy summer, that made me aware of this musty, moldy smell coming from my car vents.

It was a real stumper, and very frustrating to say the least. I had lucked out in finding a car that had no new-car or air freshener smells (hard to come by). It also had not developed mold issues inside the cabin from moisture issues besides the vents. Most people leave their windows open on a humid day or in a rainstorm at least once in a car’s life, and moist upholstery can lead to mold growth within 24 hours if it isn’t dried out by the sun, a dehumidifer, or a space heater. A lot of people also spill their beverages while driving at least once and don’t take the proper steps to clean them out.

So, you can imagine how flustered I was having everything perfect but feeling that no matter what car I chose, the vents would always end up with this odor. Thankfully, I was wrong.

I did try to safely “clean” the vents, heeding the suggestions of most websites with answers to the problem. I did this by spraying a safe anti-mold product that I trust, Concrobium, directly into the vents while the A/C was running on full blast. It is a great product that seemed to help the problem for awhile, though it did generate a different, but not unpleasant smell from the vents as the treatment settled. I don’t discourage trying this method to clear out the smell, but as this article from Kelley Blue Book’s website on the matter says, “You can kill mold with an antimicrobial treatment…but the mold will reappear.”

Whatever you do: don’t use Lysol or any other disinfectant in your car vents. These are toxic products, and you will really regret spraying them and their deployment cannot be undone!

lysol concrobium

In that concise and mostly accurate article, they go on to hint at (but they do not provide a link to) a product that prevents the root of the problem, which they have correctly identified:

The evaporator core gets wet, because humidity condenses on the core surface. Mold loves wet surfaces and it gets food from pollen in the air, dead insects or bits of leaves that blow in through the outside vents.

But I’m going to tell you the free and easy answer right here and now! You can pay me by leaving comments expressing your eternal gratitude below.

Finally, a Simple and Free Answer


Ultimately, I found the answer from asking around by word of mouth (the old-fashioned way), which is always the best way to get good answers. You might not know this, but face-to-face communication is still more efficient for finding the best solutions to problems we humans experience. Don’t let anyone tell you otherwise.

I met this guy and his family on a day trip I took over to Berkeley Springs, WV. Whenever I speak at length to anyone I meet these days, I inevitably tell them about my health issues, including allergies and sensitivities that were complications of living in a moldy home or two. Having moved from state to state their whole lives, they had also inhabited a couple houses that harbored black mold. When the conversation got around to mold in vehicles, I fortunately asked the husband, who had some mechanic experience, what he did about that smelly vent issue. He seemed to perk up, saying, “That’s easy, here’s what you do…” Then he enumerated the most effective fix I’ve ever utilized for any problem this difficult:

  • The problem is moisture building up on the evaporator
  • When the A/C shuts off after cooling (Regular or MAX setting), the moisture builds up quickly from the sudden temperature differential (condensation)
  • The answer to this is to turn off the compressor and let the fan blow before completely turning off the air conditioner
  • You can effect this by literally switching from A/C or MAX to just the Vent/Panel setting


  • You can just press the A/C button on your dash that turns the compressor on/off and causes cool air to stop blowing
  • Do this with the fan on high for just one minute before turning off your car or before turning off your A/C
  • This will dry off the compressor by blowing warm air across it (so turning the temp dial up a bit might help), at which point it will drip off

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Caveat Good News: If you forgot to do this the last time you drove, you can run the fan without the compressor for one minute before you turn on the compressor, and though it will blow a moldy smell for a few seconds, it will fix the problem for that ride. Also, if you’ve not been employing this trick all summer and have built up a significant musty smell, keep following this procedure, and do an extra minute of compressor-free air here and there, and it will get fixed! This is what happened to me.

Also, if it has recently rained or has been a very humid day, that’s another time you’ll want to run the vent on high for a minute or two before you drive.

I guarantee this will make your driving experience so much better. Considering how much time you probably spend in your car, this will provide you with a lot cleaner and pleasant air in your life.


About Rob 70 Articles
Rob was the valedictorian of his high school (his last claim to fame), but now believes that academics are overrated. He is a musician and former copy editor, and is now studying independently as an amateur nutritionist, businessman, and writer/rocker against world government and for liberty. He is also attempting to obtain a PhD in squats, deadlifts, shoulder raises, rows, bench press, dips, and pull-ups.


  1. Wow easy-easy! Ingenious! I always turn off the a.c. and leave the fan on but I don’t let it run long enough….. Clearly…. ‘Be been doing the vinegar thing but that is very temporary. Thank you so much for posting! Torre (also in MD where this summer seems so much more humid the typical….)

  2. Thanks for the info., Rob. With your comments about your sensitivity to mold, I wonder if you’ve looked into the work of Dr. Ritchie Shoemaker, M.D. @ Survivingmold.com? Many people (present company included) have genes that make us genetically susceptible to mold. Once triggered, like your prior experiences with mold, it can have an upregulating effect for future exposures.

    • Absolutely! I got my feet wet with the Shoemaker protocol, and I even took Welchol to help eliminate toxins. I continue to use Activated Charcoal for maintenance, and I avoid mold at all costs. Hence why little “hacks” like these that help avoid moldy, musty smells (even slightly so) are so important to me. And I share them with everyone like yourself!

  3. Rob, Excellent suggestion! Thanks!

    Remember the Melbourne “Thunderstorm Asthma” of Nov 2016? Killed 9 and over 8500 people went to the hospital. http://www.news.com.au/national/victoria/news/ninth-person-dead-following-thunder-storm-asthma-event/news-story/f5899c2642ae32e95e9d2a53a326f966
    Actually, it was MOLD (ergot) which caused the “Thunderstorm Asthma”.
    You can see the sources and also scientific studies which validate mold/fungi as the cause in this thread. The thread is long, but some very good validating sources. https://www.corbettreport.com/weather-is-not-climate/#comment-34327

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