How to Check and Change Your Vehicle's Air Filter

In most newer, fuel-injected vehicles, the air filter is found inside a rectangular box called a cold air collector box. The air filter is usually close to the front of the vehicle, near the inside of one of the fenders. Air that’s scooped up by the front of the vehicle moves through an air intake tube into the air filter inside the box.

On older fuel-injected engines and carbureted engines, the filter is found in the air cleaner, which sits atop the engine. As you can see here, it’s large and round with a snorkel sticking out of the side to facilitate the intake of fresh air. Your owner’s manual should have instructions on how to locate and get at your air filter.

To find out if your air filter needs to be replaced, just lift it out (it isn’t fastened down) and hold it up to the sun or to a strong light. Can you see the light streaming through it? If not, try dropping it lightly, bottom-side down, on a hard surface to jar some dirt loose. (Don’t blow through the filter — you can foul it up that way.) If you drop the filter a few times and it’s still too dirty to see through, you need a new one.

Because the air filter extracts dirt and dust particles from the air, you should change it at least once a year or every 20,000 miles, whichever comes first — unless yours gets very dirty before then. If you do most of your driving in a dusty or sandy area, you may need to replace your air filter more often.

Changing the air filter on newer vehicles

The air cleaner on newer vehicles has a large air inlet duct (also called the air intake hose) connected to it. Loosen the hose clamp that seals it to the box, and then undo all of the screws, clamps, or wing nuts that hold the lid of the box in place. Put the fasteners you removed somewhere safe so that they don’t roll off into oblivion. Open the lid of the box and . . . voila! . . . you should find the air filter inside (as shown here). Lift out the old filter (it isn’t fastened down) and take a look at it.

Some older vehicles have permanent air filters, and some off-road vehicles have more-complex filters with wet and dry elements. Clean and replace these according to the instructions in your owner’s manual.

To clean a pleated air filter, use either an air hose to blow the dirt off (not through) it or a vacuum to suck it out. For both methods, handle the filter gently to avoid crushing the pleats. Keep the nozzle of the air hose or vacuum cleaner several inches away from the filter — don’t jam it up against it. And if you’re using compressed air, do it away from the vehicle to avoid blowing the dirt around under the hood.

If the interior of the box is fouled with dust or sand, before you clean the box, place some duct tape over the open end of the air intake hose so that the dirt can’t get in. Then either use the compressed air hose to blow the dirt out of the box or the vacuum cleaner to suck it out.

When the cleaned filter — or the new one — is in place, put the lid back on the box and replace all the stuff that held it on. Then, remove the duct tape from the open end of the air intake hose and use the hose clamp to reattach it to the box. Done!