Is Your Car's Air Filter Bad? Here's How to Tell

If you're wondering if your car's air filter is bad, there are a few tell-tale signs to look out for. Black smoke, soot, or flames coming out of the exhaust, a gasoline smell when starting the car, and unusual noises like coughing, clicking, or spitting are all indicators that the air filter needs to be replaced. You can also perform a visual inspection of the air cleaner by popping the hood and looking for clogged or contaminated filters. If they're clean and you can see through them when you light them up with a flashlight, then they're probably in good condition.

The engine check light can also illuminate for several reasons, including insufficient air supply due to an excessively dirty air filter. If your car is having difficulty starting, unresponsive acceleration, delays, misfires, or the engine check light is on, then it's likely time to replace the filter. Air filters allow for mechanical filtration, trapping particles larger than the pores in their fiber composition. You may even hear a slight hiss if airflow is limited due to buildup on the filter screen.

Unless your engine air filter is spotless or barely dirty, it's OK to leave it on, but it's always up to you. For every gallon of gasoline consumed by a car, thousands of gallons of air must be ingested to process the fuel efficiently. Replacing your car's filters on a regular basis can substantially influence engine life and efficiency. If dust and grime accumulate for a long time, the air filter will darken and the dust will become visible.

A clogged air filter on an older model vehicle won't stop you from driving, but it will cause inefficient combustion of fuel within the combustion chamber and reduce mileage. Many mechanics or dealers will allow you to purchase the filter on your own and take it with you for installation. To remove the filter, first consult your owner's manual for the location of the filter and then follow the step-by-step instructions to uninstall it. A clean air filter improves the quantity and quality of air that reaches the engine and thus improves engine performance.

Replacing your car's air filter regularly can help keep your engine running smoothly and efficiently.