Some automotive problems are accompanied by a distinct odor. Use this chart to diagnose the source of any odd smells in your car.
Check that you haven't left your gas cap off. This can cause the faint smell of gas in the air. If the cap is securely on, it might point to a larger problem.
Check your tailpipe for holes, cracks or broken pieces. This can filter exhaust in to you car from various crevasses. Because carbon monoxide is dangerous to inhale, you should get you car checked by a mechanic.
Sniff around for the smell of rotten eggs, and we don't mean your fridge. The rotten-egg smell comes from a clogged or plugged catalytic converter or a very rich fuel mixture. It can also cause poor gas mileage.
Turn the engine off and inspect all rubber hoses and belts under hood if you smell burning rubber. The smell might be coming from a melting rubber hose resting on a hot exhaust manifold or a belt shredded by a jammed pulley.
Check your oil frequently. An oil leak at the top of the engine (typically from the valve-cover gasket) can spill onto the exhaust manifold and burn, causing a foul smell and occasionally light smoke.
Take your car into your mechanic. If a smell persists, and you can't locate it, take your car into and auto-repair shop. While not all foul smells mean danger, they're certainly not good news for your car.
