Automotive Repair Blog: Tips, Facts, and Fixes



If your A/C smells a little weird, you’re not alone and there are easy ways to get the smell out.

In 2015, Americans drove more than 3.15 trillion miles, and with low gas prices this summer we’re not slowing down! You excitedly head out the door for your summer plans, turn on your favorite playlist, crank up the A/C and your nose is suddenly assaulted with an odor similar to that of an old dirty gym sock. Wondering what that strange smell is coming out of your A/C? We hate to break it to you, but that smell is most likely a build up of mold, fungus and/or bacteria that’s found a nice home in your A/C unit. Gross!

What’s Causing the Smell?
Unfortunately this is a pretty common problem for vehicles, so let’s break it down and understand the basics. The component within your A/C unit called an evaporator works as a de-humidifier to help chill the air before it enters the cabin. As cold air is pulled through the evaporator, water molecules from the warmer outside air create condensation around the unit. It’s just like how condensation builds up on your glass of ice tea while you’re sitting on the porch in the summer. High five to science!

Ever wonder what that puddle of water was on the pavement underneath your car on the passenger side? That’s the excessive buildup of condensation dripping off the evaporator. This condensation builds up on the evaporator and creates the ideal place for mold, fungus and/or bacteria to grow.

Out with the Odor
Since this awful smell coming out of your A/C vent is such a common problem, there are luckily a few remedies to get the odor out.

#1 – The first step is to use a clean air evaporator cleaner, such as DWD2. Without the use of harsh chemicals and toxins, a clean air evaporator cleaner is a foaming detergent that will penetrate deep into your car’s evaporator and breakdown the mold and other culprits that are causing the odor. This cleaner will not only eliminate the odor, but will also increase the evaporator’s efficiency allowing you to have cooler air!

#2 – If the clean air evaporator cleaner doesn’t seem to do the trick, which may be the case for more severe mold buildup, try changing out the cabin air filter. The cabin air filter is responsible for cleaning the air before it makes its way into the cabin of the vehicle. The cabin filter can become clogged with dust and debris and is yet another place that mold likes to call home. Cabin filters are a little trickier to change since they’re typically located behind the glovebox, and Pro Auto Care is happy to help!

#3 – If the smell still persists, give Pro Auto Care a call and we’re happy to take a look. A professional foaming system cleaner is one of the most effective ways to get the smell out of your A/C vent, but should always be done by the pros.

Keep it Odor Free
Once the smell is out of your A/C, there are a few best practices to keep it from coming back. Switch between fresh air and recirculated air to help keep your car’s HVA/C (Heating, Ventilation, and Air Conditioning) system dry. Switching between the two will cut down on the condensation buildup on the evaporator, which will help prevent mold, fungus and bacteria from growing.

So if you’re suffering from the odor in your A/C unit, Pro Auto Care is here to help get that nasty smell out. Call us or make an appointment online, your nose will thank you for it.

We look forward to helping you enjoy the summer ahead!