In with the good air, out with the bad

We’ve all taken day-long road trips. Besides the depleted gas tank at the journey’s end, dust typically powders the hood and gook (formerly insects) glops across the windshield.

Guess what? Those particles and winged things also have been sucked under the hood via your vehicle’s air-filtration system.

An air filter being removed from its housing.

The first line of defense for your engine’s innards—the air filter—hopefully has been doing its job by catching these potentially clogging contaminants. But why simply cross your fingers, when a simple—and we do mean “simple”—air-filter check will do the trick? Did we mention the gas-robbing characteristics of a dirty air filter? It’s about 2 miles per gallon. (For more info, click here.)

Many auto experts say drivers living in non-Sahara conditions should swap their air filters for new ones annually or at the 15K-to-20K-mile mark. Others say do it more often based on visual inspection, which is easily accomplished by even the most techno-phobic individuals.

First, locate the air-filter housing, sometimes known in carspeak as the “cold air collector box.” On most newer fuel-injected vehicles, this will be a rectangular unit located under the hood near a fender or the radiator. It probably will be secured via several easily removed clips or, in some cases, wing nuts. Older cars (fuel-injected or carbureted) typically house a larger, round filter within the air cleaner, which is situated on top of the engine. These usually require removal of a screw to access. You always can check your owner’s manual for the precise location. In either case, the filter will consist of either pleated paper or plastic surrounded by a rubber rim.

Open the housing and simply lift out the air filter. A less-than-pristine appearance isn’t necessarily the mark of a malfunctioning unit, so take the following steps to ensure a proper assessment. Hold it up to sunlight or another source of powerful illumination. If light is visible through the filter, then it’s still doing its job and can simply be put back into the housing. If the light is obscured, you can try dropping it top-side up onto a hard surface. This might shake some soil loose. It could take several tries to get it to work.

If light is visible after this procedure, then the filter still is functional. If not, it’s time to pop for a new one. Simply place the old filter back in the car and head to the nearest auto-parts retailer for a replacement.

Remember, when attempting to dislodge contaminants, do not blow through the filter. This is a sure way to wreck it. Also, never—we repeat, never—run or drive a vehicle with the air filter removed.