Clear the Air | How to Assess Car Odors

While driving, one of the most frustrating things that can occur is getting a whiff of an odor that is not normal for your car. Knowing what different car smells mean can help you better diagnose your vehicle’s problem and get it properly fixed.

Hydrogen sulfide in your exhaust could be causing your car to smell like rotten eggs.

If you are like me, having a foreign smell arise in your car can be frustrating. That is why we at Sallas Auto have taken the time to put together a list of top car odors and how to clear them out of the air, literally.

Rotten Eggs

If you have ever turned your car on and smelled rotten eggs it is time to check the exhaust, not for eggs, but for hydrogen sulfide. Hydrogen sulfide is produced when your catalytic converter is not working correctly. If you smell eggs you should definitely take your car into a trusted auto shop, the smell suggests you have trouble. A trusted shop will be able to tell you if it is a fuel problem or if you need a new catalytic converter.

Smelly Feet

You may think it’s hard to distinguish between rotten eggs and smelly feet, but once you get a whiff of either one, you will know how distinctive each odor can be. If your nose catches wind of a smell that reeks of gym socks when you turn on your air conditioner or heater it most likely means you have a mold problem.

When your evaporator gets too moist it begins to house mold and mildew. The great news is that you can fix this smell yourself. Simply dry out your evaporator by turning your a/c or heat off and just run the fan for about 10 to 15 minutes. If after doing this a few times and it doesn’t work, bring it in to your local auto shop for a look.

Burning Newspaper

If you have ever used a newspaper for firewood kindling you know the smell it carries. If you own a stick shift and a burning paper odor begins to arise, it is most likely because your clutch is slipping as you change gears. This could be because you are not using the clutch pedal correctly or because you need to replace the clutch all together. You can diagnose the problem by testing the clutch pedal. Let another person drive your vehicle and see if the same odor occurs when they shift gears.

Burning Oil

You may smell oil burning if you have an oil leak in your valve or crankshaft that is making it’s way to your exhaust manifold. This is why it is always good to do preventative maintenance on your vehicle. Having your oil checked frequently will increase your ability to catch these leaks before they happen, which will save you money.


If your car smells like it is leaking gas, you should definitely be sure to check. Older vehicles, especially, have a higher risk of leaking gas. And if your car is parked in a garage, having a gas leak can mean serious danger.

A gas leak can be caused by a number of variables such as the ignition timing being off to the fuel regulator being set too high, but finding the leak is the most important. If your car smells like gas, take it immediately to a trusted mechanic. They will be able to accurately diagnose the problem and make your car as safe as possible.

So next time you are in your car and an odor arises having you say, “what’s that smell?” take the time to investigate the odor. If your lucky it may just be a little mildew! Take the time to invest in your vehicle and keep it running to its best ability.


Car Odors