Noticing a Strange Smell Coming from Your Car? What Could It Be?

If you've noticed a strange smell when you are in or around your car, you will likely be worried that something is wrong. While you look up the number for your mechanic, it helps to gather some information in order to help them pinpoint the issue. What should you suspect with these different types of smell?


If you notice a very "sweet" smell, this could be caused by one of these issues. When you're driving along, then you may have problems with the heater core, as coolant or antifreeze could be leaking into the passenger compartment floor area. If you tend to notice it more in or around the engine compartment when the engine is running, it could be due to a faulty or leaking water pump (or associated gasket), or ineffective radiator drain plug.

Burning Metal

If your bloodhound-like nose tells you there is a smell of burning metal when you're driving, where it is emanating from? If it's coming from the front or rear of the car then it is likely due to faulty wheel bearings or hubs. If it is coming from a direction that seems to be more below you, then it is likely due to a clutch bearing in the transmission which is on its way out.

Burning Plastic

If you notice a smell like burning plastic when the engine is running then this could be due to wires which have become dislodged and are touching the hot engine. It could also be due to an issue with your battery cable which is corroded, or may be shorting out.

Exhaust Gases

If you notice a very strong exhaust gas odor when the car's engine is idling, then you need to look at the manifold or serpentine system next to the engine, which routes the gases to the rear of the car. It is likely that this is either loose or may be suffering from rusting.


If you notice a strong mildew or mold smell when you first get into the car, then ask a mechanic to inspect the heater core, as it may be leaking fluid into the floor area, causing mildew accumulation in the humid interior. If conversely, you notice this smell in the boot of your car then it's possible that the weather stripping is damaged and rainwater is entering and being trapped in this area.


Finally, if the smell is more like "rotten eggs" when you are driving, this could be due to either a faulty oxygen sensor or a clogged catalytic converter. It is also possible that the carburettor is not functioning properly, or that the ignition timing needs to be reset correctly.

Time to get on the phone!