Is there a funky smell in your car — especially when the air conditioner or heater is on? If it smells musty like a sweaty sock, the car care experts at Consumer Reports have some easy ways to defunkify your car’s air so you can breathe easier.

Unless you left your teenager’s gross sports uniform in the car, Consumer Reports says you probably don’t have to sniff around to find the culprit of that not-so-pleasant odor. You’re probably smelling condensation from the evaporator inside your heating and cooling system. Water collects in that area, and if it sits long enough, it creates a musty smell.

Most of the water is meant to exit the car through the evaporator drain under the vehicle. You’ve probably seen a small puddle of water under your car, but sometimes, that water collects in the evaporator and if it sits in there for a while, bacteria and mold can form, causing that smell.

The good news is the solution likely won’t require a trip to the mechanic. It’s an easy fix you can do yourself.

First, turn the fan to the low setting and open the windows. Get a disinfectant like Lysol and spray it into the climate system’s air intake, also known as the plenum. The plenum is located at the base of your windshield, where your wipers are located. It’s where the air comes from that goes into your heating and cooling system.

With the engine on and the interior fan running, spray plenty of cleaner on both sides of the plenum intake vent and the fan will pull it into the system, where it will kill the bacteria and help get rid of that musty odor. Keep the windows open to help air out the car.

If you have a cabin filter, remove it before spraying the disinfectant to help it move through the system. It might be a good time to change it, too, because a dirty filter can prevent optimal airflow and changing it yourself can save you money and time.

Another source of a musty smell might be the sunroof. There are small drainage holes on the sides, which sometimes get clogged, allowing water to seep into the roof’s liner or even drip onto the seats.

---

All Consumer Reports material is Copyright 2024 Consumer Reports, Inc. All Rights Reserved.

Consumer Reports is an independent, nonprofit organization and has no relationship with any advertisers on this site.

Consumer Reports does not endorse products or services, and does not accept advertising.

For more information, visit consumerreports.org.