How to Rid Your Car of Odors and Smells

Before he came to CR, lead auto technician Mike Crossen worked at car dealerships where he encountered plenty of unpleasant odors in customers’ cars. The culprit was often obvious—spilled food, dirty gym clothes, or cigarette smoke. To prevent those odors, there’s an easy solution: Keep your car clean.

“Simple regular cleaning helps a lot—not allowing the smelly things to accumulate in the car in the first place,” he says. Toss any leftovers or trash before they can stink up the car, and wipe up or vacuum any dirt you’ve tracked in as soon as you can.

Some odors are more elusive, however, and require more effort to diagnose. “Water leaks, blocked AC drains, not changing the cabin air filter—these can all lead to unpleasant smells,” Crossen says. But fixing those problems requires more effort. That’s why he recommends using the process of elimination to find where the smell is coming from.

Search under seats for old french fries or cereal, for example. Check the cup holders for spilled coffee. Remove the floor mats and shampoo them at a hand car wash or at home using a solution of water and detergent (more on those below).

While the floor mats are out, it’s time to vacuum the carpets. Before vacuuming, sprinkle them with baking soda and let them sit. Make sure the carpet is dry, or the baking soda will clump. 

Once you’re done, leave an open can of coffee inside the car overnight—a trick we learned from a car wash owner. In addition to having a pleasant scent in their own right, coffee beans act as a deodorizer.

For cleaning interior surfaces, Crossen and others recommend cleaners meant specifically for cars, but some household cleaners will also work. When we interviewed Jeff Stout from Yanfeng, the world’s largest supplier of automotive interior parts, he said that isopropyl alcohol is a safe way to kill any germs on a car’s interior surfaces. In fact, it’s what Yanfeng uses in its own factories. “We will use that to clean smudges or any kind of last-minute details before we ship the product,” he told us.

But don’t use bleach or hydrogen peroxide, because they are likely to damage your car’s upholstery. Likewise, ammonia-based cleaners can damage the anti-glare and anti-fingerprint coatings on car touchscreens. Simple Ivory soap and water will do the trick on leather, according to Dara Ward, a spokesperson for automotive leather supplier Katzkin. Don’t scrub too hard, because you may wear off your leather’s protective finish.

As far as cleaning cloths are concerned, we recommend using clean microfiber towels because they won’t scratch delicate surfaces or leave lint behind. That’s especially true on many newer cars, which have shiny black plastic interior trim pieces that are extremely easy to scratch.

If the air coming out of your car’s vents smells like a high school locker room, the problem likely has to do with your climate control system. “What you’re probably smelling is the condensation that comes from the evaporator inside your heating and cooling system,” says Jake Fisher, Consumer Reports’ senior director of auto testing. “Basically, water collects in that area and, if it sits long enough, creates the musty smell.”

You may have heard of “odor bombs,” also known as foggers. These aerosol cans automatically spray a scent while the vehicle is unoccupied. After a few hours, the smell is gone—or at least that’s what the advertising says.

Crossen warns that many of these products simply mask a smell with another scent, which some people might find bothersome or irritating. He says to look for products that include chlorine dioxide as an ingredient—like this one, available online—because the chemical can actually eliminate odors.

Still smelly? In most cases, Crossen says, DIY cleaning is just fine. But if that smell doesn’t go away, it may be time to reach out to a detailer—or even a mechanic.

A professional detailer may have special tools that can outperform what you’re able to do at home. For example, an ozone generator emits odor-destroying ozone gas that can permeate every corner of your car’s interior—even the ones you can’t reach with a cloth—but could be hazardous to your health if not used properly. “Ozone machines work great to eliminate lingering odors,” says Crossen, who prefers them over odor bombs. If you choose to use an ozone machine yourself, like this one from Alpine Air, make sure to read the instructions because inhaling ozone gas can harm the lungs and exacerbate breathing problems. Never use an ozone machine in a space where people or pets are present.

If your car has a moldy, musty odor, it could be the result of a blocked drain—from either your air conditioner or your sunroof. First, you should check for and remove any leaves or obvious debris that are blocking the sunroof drains, which you can find by opening the sunroof and looking down at it from above. The drains are usually at the corners of the black rubber gasket that surrounds the opening. Be gentle because damaging the gasket could cause leaks. CR’s mechanics say to beware of online tutorials that tell you to use compressed air to clean a sunroof drain; that can cause damage. If it’s your AC, you might even hear sloshing sounds when you turn. In either case, a trusted mechanic should be able to help.

Occasionally, our test cars develop the telltale odor of a decaying rodent. That’s because mice and other creatures like to make homes inside cars—especially if they aren’t used often. You can read our tips on how to keep that from happening, but if it’s too late, your car might need a serious cleaning. If a car is truly infested to the point where interior components need to be replaced, your car insurer might even consider it a total loss.

The same goes if your car’s interior got really wet—either from a blocked drain or from forgetting to close a sunroof or windows during a rainstorm. Remediating water damage often requires tools and skills beyond what most people have in their own garages, and not doing the job right could have serious consequences.

“Water and mold or rodent problems can cause health issues, and need to be dealt with accordingly,” says Crossen. “Interior panels may need to be removed or replaced, and if there is mold accumulation, it needs to be cleaned with specific cleaners that work on mold.”

If you smell something sweet or fishy coming from your vents, it could be a sign that your car’s heater core is bad. Those odors may be due to leaking coolant, and it’s a sign you need to fix the problem right away. Otherwise, your car may lose the vital coolant that keeps your engine from overheating. It could even lead to engine damage.

As it turned out, my musty wagon was suffering from a blocked sunroof drain. The cabin air filter was filthy, and—sure enough—I found fur from the prior owner’s dog underneath the floor mats. 

The solution was easy enough: I had a mechanic clean out the AC drain the next time the car was in for service, then I gave the carpet a good shampooing and changed out the cabin air filter by myself. Total cost? Under $100. And I got it smelling clean and fresh before anyone else noticed.