5 Smells & What They Can Tell You About Your Car

3 May 2017
 Categories: , Articles


Your sense of smell can tell you a lot about your vehicle. Following are six smells and what they can tell you about the mechanical condition of your car.


Smelling fuel in your car's interior could have an innocuous explanation such as getting fuel on your feet while gassing up at a service station. But don't dismiss it lightly -- it could be the first sign of a serious issue. Persistent interior fuel odors can be caused by leaks in the gas lines or the fuel injectors, and, if left untreated, can result in dangerous situations such as fire under the hood. After you rule out less serious causes, get it to a mechanic ASAP.

Exhaust Fumes

It's not unusual to smell exhaust fumes if you are driving with the window down—the fumes of traffic will come into your vehicle's interior on the breeze—but if you smell exhaust fumes while driving with all your windows up, you need to address the problem immediately.

Even though the problem could be something as simple as a leak in your door seal that's letting outside air into the vehicle, it could also mean that you've got a leak in your exhaust system. Because exhaust contains carbon monoxide, which can cause illness or even death if too much is inhaled, you should always err on the side of caution and have a mechanic look at it right away. 

Rotten Eggs

If your car smells like rotten eggs, it's possible that you've got a malfunctioning catalytic converter on your hands. All automotive fuel contains small amounts of sulfur, which is normally converted to odorless sulfur dioxide when it passes through the catalytic converter. However, if the catalytic converter isn't functioning properly, the sulfur won't be converted into a substance that doesn't smell. Catalytic converters generally require replacement rather than repair.

A lesser cause of a rotten egg smell is that your engine is running too hot, which also prevents the catalytic converter from doing its job. In some instances, a rotten egg smell may be caused by a battery that is overcharged. If you notice a rotten egg smell, you need to take your vehicle to a mechanic right away so that the cause can be discovered and fixed. 

Something Sweet and Cloying

The smell of coolant, or anti-freeze, is often referred to as sickeningly sweet. This overly sweet smell is caused by a compound called ethyline glicol, which can be fatally toxic to both humans and domestic pets if ingested. If you smell it in your vehicle, it's likely that your vehicle has a leak in its cooling system. A leak in the heater core, which is the element that heats the interior of the car,  may result in a puddle on the floor of the passenger side of the vehicle.

The problem could also be caused by a leak or leaks in the hoses or pipes of the system that cools the vehicle's engine. The first sign of this may be puddles of coolant in your driveway or garage where the vehicle has been parked. Coolant comes in both orange and bright green—these colors are designed to help you identify if if your car springs a leak. It is very important to mop up all signs of leaked coolant immediately—its sweet smell and taste make it tempting to domestic pets. 

Something Burning

Burning smells have a variety of potential causes. You may notice a burning odor if your vehicle's clutch is malfunctioning, or it could be possible that oil is leaking onto your car's engine. Engine belts that fail typically emit an odor of burning rubber. Any burning odor that persists should result in a trip to the repair shop.

To learn more about weird or bad car smells, contact local Nissan repair centers.