Whether it’s a musty smell or the result of a spill, here’s how to fix it—and keep it from happening again

“Sorry to tell you this, Keith, but your car stinks.” My friend’s words confirmed my suspicion: Yes, the used station wagon I’d just bought had a clean vehicle history report and all its service records—but it also had a serious odor problem. To make matters worse, I was supposed to drive three other people to an event later that week.

If you’ve ever been in a similar situation—wrinkling your nose at the scent of your own vehicle as your thoughts drift to the “smelly car” episode of “Seinfeld,” where Jerry’s BMW inexplicably smells “beyond B.O.”—we have good news for you: That stench might not be your fault. And even if it is, you can fix it. We’ll tell you how.

Consumer Reports’ in-house mechanics—the same ones who keep our fleet of test vehicles running smoothly and sparkling fresh—gave us tips you can use for your vehicles, even if mice made a home under the hood or you left the sunroof open before a rainstorm. We also reached out to car wash operators, cleaning product manufacturers, and car interior designers to find out how they tackle odors.

Here’s what you should do.

Those nooks and crannies for cups and change can accumulate crumbs and spills that start to smell over time.

Before he came to CR, 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.

Even if you use a seat cover, your furry friends can leave smells behind.

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.

Your car's heating or AC system might be responsible for some persistent odors.

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 can fix the problem yourself with AC disinfectant you can buy at an auto parts store, or with Lysol aerosol spray. First, turn on the car’s interior fan on the low setting and open the car’s windows. Then spray the disinfectant into the AC intake vents, which can be found at the base of the exterior side of your windshield, near where your wipers are located. For more details, read our complete guide to fixing a musty AC.

While you’re at it, change your cabin air filter. This filter keeps the air inside the car free of allergens and contaminants and is usually accessed through the glove box. Some are simple to reach; others aren’t. Dealers often charge a lot more than the cost of the filter itself, so it’s a good idea to do it yourself if you can. Instructions can often be found in the vehicle owner’s manual. John Ibbotson, CR’s chief mechanic, says YouTube instructional videos can also be helpful.

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. He says to look for ones that include chlorine dioxide as an ingredient because this chemical can actually eliminate odors.

Sunroofs have drains that can get clogged. If you don't clean them out, a nasty odor might develop.

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. “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, make sure to read the instructions because inhaling ozone gas can harm the lungs and exacerbate breathing problems.

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.

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.”

On most cars, this is where you spray the AC cleaner.

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.

More from Consumer Reports: Top pick tires for 2016 Best used cars for $25,000 and less 7 best mattresses for couples

Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2022, Consumer Reports, Inc.

The Fox News host, who has never served in the armed forces, can't stand women in the military, even though they're often praised by its leaders.

Applied Materials (NASDAQ: AMAT) revised its fiscal fourth-quarter outlook on Oct. 12 in response to the Biden Administration's new restrictions on the export of semiconductors and semiconductor equipment to China.

It had a classic Piscataway-Sayreville feel to it, in which the teams often met as among the best squads in the area.

It takes preparation and commitment: Julia Lapolla explains why she committed to running 50 half marathons within six years.

In the last year, multiple insiders have substantially increased their holdings of Brown & Brown, Inc. ( NYSE:BRO...

Oct. 15—COLUMBIA FALLS — Cody Schweikert ran for one touchdown and threw for another and the Columbia Falls Wildcats downed the Whitefish Bulldogs 24-20 on Friday in Western A football. Schweikert was 21-for-30 passing with 237 yards and carried the ball 21 times for 90 yards. The Wildcats trailed 20-17 in the fourth quarter when Reggie Sapa ripped off a 14-yard touchdown run that gave the ...

Oct. 15—BIGFORK — In a rematch of last year's State B championship, Bigfork edged Florence 20-19 Friday in a Western B football game that came down to the final minutes. The defending state champion Falcons roared back from a 14-0 deficit with three rushing touchdowns from Patrick Duchien, two in the fourth quarter. Suddenly down 19-14 with 1:32 left, the Vikings got the winning TD, an 11-yard ...

Oct. 15—The Crosstown football game went Glacier's way again Friday, mainly because Gage Sliter packed an entire game into one half. The senior quarterback threw five touchdown passes in the first two quarters at Legends Stadium, leading the Wolfpack to a 42-0 lead over Flathead that held up for a 49-14 win. Jackson Hensley added 119 rushing yards and the first touchdown of the day, a 4-yard ...

Most investors don't think of real estate investment trusts (REITs) as growth stocks. Analysts predict this growth stock could soar as much as 40% by 2023. The last few years were exceptionally prosperous for the REIT.

While virus-related hospitalizations remain distressingly high, the decline from peaks has boosted profits for UnitedHealth and other insurers

The Tampa Bay Lightning visit the Pittsburgh Penguins after Steven Stamkos’ two-goal game against the Columbus Blue Jackets in the Lightning’s 5-2 win.

Stage adaptations of Strange Case of Dr Jekyll and Mr Hyde proliferated swiftly on the heels of the novella’s publication in 1886, and as gaslight gave the way to electricity and cinema arrived, the big screen followed suit.

Taking the occasional loss comes part and parcel with investing on the stock market. Anyone who held Sify Technologies...

Each year, usually in October, the Social Security Administration announces the cost-of-living adjustment (COLA) increase for the following year. With the Consumer Price Index (CPI) for September 2022...

Investing is all about making your money work for you - getting money without having to actually perform labor. But what some investors may initially neglect to take into account is the fact that investment gains mean investment income, and … Continue reading → The post 2022 and 2021 Capital Gains Tax Rates appeared first on SmartAsset Blog.

Social Security serves mostly older retirees, but also the disabled through Social Security Disability Insurance (SSDI). The Supplemental Security Income (SSI) program gives extra help to the most...

This week, social media made me do this.View Entire Post ›

Airbnb, Inc. ( NASDAQ:ABNB ) shareholders should be happy to see the share price up 15% in the last quarter. But in...

When you delay Social Security benefits beyond your full retirement age, your benefit amount will continue to increase up until age 70 with a maximum monthly benefit of $4,194 in 2022. Social Security...

Medicare open enrollment starts today, but 7 in 10 Medicare beneficiaries say they don’t compare Medicare plans during this period, according to a 2021 analysis by KFF, a health policy…