7 Car Smells You Should Never Ignore

Not able to do it yourself? No problem. Find an attendant or mechanic at the station who can help.

If the tire pressure is normal, Watson says, the burning rubber smell could signal trouble with the brakes or the drive belt slipping, which are reasons to have a mechanic give your car a once-over as soon as possible. Wait too long, Watson warns, and the issue could leave you stranded on the side of a road.

Burning oil

Motor oil lubricates the engine, reduces friction and helps regulate engine temperature. A thick, acrid smell, especially if the dashboard’s oil pressure warning light comes on, can indicate your car is burning or leaking oil.

What to do: If you smell burning oil, Watson recommends having your car looked at immediately. There is a risk of fire associated with this smell. Checking your oil is step one, and you might be able to do this yourself. Open the hood, locate the dipstick, pull it out, wipe it off with a rag, reinsert it and pull it out again to check the level by looking at the notches on the dipstick, Watson advises.

If the oil level is low, look for signs of leaks. “Noticeable wet spots on your engine or below your car [after it’s been sitting in the driveway] can indicate an oil leak, as can a strong oil smell during or after driving,” he says.  

Maple syrup

A sweet smell sounds like a good thing, but it could mean the car is leaking coolant.  

Coolant is a 50/50 mix of antifreeze and water, and as its name suggests, it plays a crucial role in controlling the engine temperature, preventing it from freezing or overheating. Watson compares the smell of leaking coolant to maple syrup and says ignoring the saccharine scent could lead to engine failure.

What to do: To check coolant levels, turn the engine off. Watson notes that the engine should be allowed to cool because there is a risk of severe burns from opening the radiator cap. Once the engine is cool to the touch, look for the clear plastic tank known as the coolant reservoir. A line on the reservoir indicates the ideal level.

“If the coolant level sits below the lower guide mark on the tank, it might be time to add more coolant, so it sits between this mark and the one above it,” Watson says.

Be aware that burning or leaking coolant could be a sign of a larger issue, so it might be time for a trip to the mechanic.

Burning plastic

This often indicates overheating components or electrical issues that can be a fire hazard, Horvat says.

What to do: The moment you get a whiff of burning plastic, Horvat advises, pull over to a safe location, switch off the engine and don’t restart the car. “Attempting to drive further could worsen the problem and increase the risk of fire.”

You shouldn’t even risk driving to a mechanic. Instead, call a tow truck for a lift.

Musty or moldy odor

If your car smells like a gym locker (and you aren’t storing your socks in the back seat), it might mean moisture has collected in the air-conditioning system, Watson says.

That might not damage the car, but it can harm your health. Research shows that car AC systems can increase air pollution and microbial contaminants in the vehicle, causing irritation, allergic reaction and even infectious disease.

What to do: Watson suggests having a mechanic identify the source of the mold and mildew scent, then thoroughly disinfecting it, which should eliminate the smell and improve air quality in your vehicle.

Metallic odor

Steel, aluminum, copper, platinum and other metals are among the main materials used in auto manufacturing. Amid all the different parts made of metals, the scent could mean multiple things.

Among several possible explanations, Horvat points to issues with the engine, low oil levels causing engine components to wear, or overheating brakes.

What to do: Regardless of the specific cause, a metallic scent means it’s time to pull over. “I would recommend that the car be towed,” Watson says, “as to prevent further damage to components that would cost more than the tow.”