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The Nose Knows: Odd Car Smells and What They Mean

catalytic converter

Your nose is an effective detective. When chemical molecules are released, smells enter your nose, dissolve within a mucous membrane and are immediately transferred to your brain to decipher. However, not all odors are easily interpreted, including certain odd car smells that could signal an even greater problem.

Here’s what those smells may or may not mean and what action should be taken.

Breakfast Most Certainly Is Not Being Served

You’re driving down the road and a very familiar breakfast smell is recognized, specifically sweet syrup. Trouble is, it’s early evening and no restaurants are serving pancakes at that hour. What you may be smelling is ethylene glycol, a key ingredient in engine coolant. The radiator or a hose may have sprung a leak, emitting this odd car smell into your cabin. Have this problem checked immediately — it could be as simple as changing a hose or a heater core.

Not Quite Burning Rubber

A pervasive burning rubber smell points to a problem that has nothing to do with your tires. Instead, burning rubber usually indicates a shifting drive belt or a loose hose, the latter rubbing against another object such as an accessory drive belt. Don’t lift the hood to scope it out until the engine cools.

Replacing a brake pad can eliminate a burning smell.Your Carpeting Probably Is Not on Fire

A burning carpet smell while driving is usually related to your brake pads or shoes. But don’t stress, the odor is perfectly normal if you’ve been using the brakes a lot. Should the smell persist, however, check the brake pads & shoes to determine whether they need replacement or if the brakes are sticking.

A Locker Room Smell to Remember

Ah, gym socks. When they’re pulled fresh from the dryer, the cottony smell is pleasant. Not so when dirty gym socks have been sitting for days, left uncleaned in a locker. Odd car smells that mimic dirty gym socks is actually mildew forming inside of your air conditioner evaporator. The solution here is usually an easy one — turn off the air conditioner and run the fan on high for several minutes, then the problem should clear. If the smell doesn’t go away you may need to have the evaporator cleaned by a qualified mechanic.

Rotten Eggs?

You did remove the eggs from the trunk the last time you shopped, right? If so, that rotten egg odor coming from underneath your car may point to a serious problem. Namely, a failed catalytic converter. The sulfur-like smell might point to a fix as simple as replacing a fuel injector, but it could also mean pulling out your warranty to see if the catalytic converter is covered.

A Seriously Hot Scoop

Have you ever placed a tightly rolled newspaper in the fireplace and watched it burn? That smell of burning newsprint is unmistakable, one your trained nose will never forget. Notice the odor in a car equipped with a manual transmission and you may find that the clutch facing is burning off as the clutch slips. Simply quit riding the clutch and the smell may go away. But if the problem persists, replacing the clutch may be in order.

Odd car smells usually point to a specific problem, one that you may be able to solve on your own. Addressing problems quickly can help you avoid a breakdown and the corresponding high cost of repairs.

Check out all the maintenance parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on odd car smells, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo courtesy of Wikimedia Commons.


Matthew C. Keegan View All

Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.

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