What’s That Smell?

Learn how to rid your car of unpleasant odors.

The unfortunate truth is, after that wonderful “new car smell” fades away, you may not like what you whiff.

It could stem from a pet accident or undiscovered remains from a fast-food meal purchased (and forgotten) far too long ago. Or perhaps your vehicle is simply old. Then, there’s always the possibility that a performance-related issue is behind the foul fragrance. Whatever the case, the following tips can help you reduce the odorous offense and save you hundreds of dollars in resale value—or keep you from getting stranded by the roadside:

Clean sweep. It may sound obvious, but many owners fear that something serious is wrong, when all the vehicle needs is a good scrubbing. “Keep the inside and the outside clean,” says Daniel Monroe, education manager at the Sacramento campus of Universal Technical Institute, one of the nation’s top providers of automotive technology education. “This will help to ensure that daily smells due to the ‘human factor’ don’t mask any serious issues.”

Diagnostic screening. There are smells that serve as a warning to get your vehicle into the shop. Musty and moldy odors could be coming from mildew growing in your A/C evaporator or vent, Monroe says. Smoke conveys burning wires, or the carpet burning from the catalytic converter overheating. That rotten-egg sulfer-y smell may mean that the catalytic converter is going bad, or a gear lube is leaking from the manual transmission, transfer case or differential housing. A sweet smell often results from leaking coolant.

A gas odor, especially when parked inside a garage, commonly is attributed to a fuel-systems leak. “That’s a potential fire hazard,” Monroe says. “It’s best then to park it in a safe, outside location and get it to an auto technician.”

Dead critters. Yes, it’s quite possible that a small rodent will somehow find comfort in your vehicle during extreme weather, and then die. This will lead to a decaying smell when you run the ventilation system. DoItYourself.com suggests having your car’s undercarriage cleaned. Then spray into the vents a solution of two cups water and half-cup of vinegar.

Dusty trail. Dust can also pile up inside the vents and lead to a musty odor. In this case, vacuum the vents and use the water-vinegar solution on the interior.

Bag it. In many cases, bad smells evolve after years of simply leaving trash in the car, especially old meal containers, drink cups, candy wrappers and the like that still have traces of food. In this case, the best offense is a good defense: Keep a small trash bag within arm’s reach of all sections of the vehicle, and make sure everyone properly disposes of all garbage before exiting the car.