Working in the automotive repair industry can be entertaining at times. The more amusing of days come when people come into the shop and describe the odors that emit from their vehicles. People have related stories of their vehicle emitting odors from everything from maple syrup to gas (and I’m not talking about petroleum). The truth is your vehicle is capable of emitting all sorts of odors. Those odors can tell your mechanic many things about your car.

The smell of rotten eggs is a frequent complaint. This smell is actually hydrogen sulfide emitting from the exhaust system. Hydrogen sulfide in the exhaust, which is produced by trace amounts of sulfur in gasoline. It's supposed to be converted to sulfur dioxide in your catalytic converter. This may be indicative of a fuel-injection problem, and can be cured by a sharp mechanic. But often it means a failed catalytic converter. 

Burnt carpet is another smell frequently mentioned. It’s usually mentioned in combination with using the brakes excessively. That burnt carpet smell isn’t carpet, its your brakes! The brake pads are overheated. This is perfectly normal after riding the brakes coming down a long mountain pass. But, if you live Florida, chances are your brakes are dragging which is usually caused by a seized brake caliper piston. It’s a dangerous smell that could ignite your car into flames if ignored. Have your car towed to a shop immediately.

As far as the maple syrup smell I mentioned earlier, that’s the smell of engine coolant. It’s also described as the smell of almonds. Engine coolant contains sweet-smelling (but toxic) ethylene glycol. Coolant is leaking from somewhere. It could be coming from a radiator or heater hose, a failed intake manifold gasket or cylinder head. It might be coming from a leaky radiator cap or the radiator itself, especially if you smell it outside the car. A strong odor inside the passenger compartment probably means a bad heater core.

Have you ever turned on your AC and got the smell of smelly gym socks? In older model cars that’s the good old smell of mildew. Newer vehicles are equipped with cabin air filters. That foul locker room smell means it’s time to change the cabin air filter.

Don’t be afraid to tell your mechanic about the odors your car is making. It helps them identify the source of the problem. Just be sure the odors are coming from your car and not your spouse.