Air Filters – You Find Them In The Strangest Places

Back in the good ol’ days, automotive air filters were simple to find; they sat right on top of the engine in a round metal container. All you had to do was unscrew a wing nut, lift off the lid, and lift out the round air filter element. A quick wipe of the debris out of the bottom of the housing, and you could drop in the new filter, replace the lid and wing nut, and be on your way.

But now, with the trend toward smaller, lighter, more fuel efficient cars, the engine compartment has become smaller therefore reducing the manufactures options to place the air intake as well as the air filter which allows for clean, fresh, cool air to enter the engine for optimal performance.

According to Kevin O'Dowd, Director of Marketing & Communications at MANN+HUMMEL Purolator Filters NA LLC, the result is that you’ll find some very creative sizes, shapes, and locations of engine air filters in today’s cars. This means that air filters are not where you are used to finding them. The good news is, once you know where they’re located, they’re almost always very simple to replace.  

Where Do You Look?
In general, expect to find your air filter located somewhere in the (usually black plastic) duct work that runs from the grille area to the top area of the engine. Your clue is usually a series of 4-6 “flip clips” that unsnap to reveal your air filter after separating a piece of the housing formerly held in place by the flip clips. With the air filter element now exposed, you can simply lift it out, noting the orientation so you can install your new filter properly.

In some cases, you’ll need to scan the full length of the duct work to locate the filter housing, explains O'Dowd. The filter may be located as far front as right behind a headlight, somewhere in the middle, or right over top of the engine. And not all filter housings use flip clips. Some use Phillips-head screws to hold the housing in place. Other applications may use hex bolts and/or nuts.  

What Can You Expect To Find?
Most of today’s air filters are of a flat panel design, which minimizes space requirements while offering the maximum surface area for optimal filtration with minimal restriction to air flow. And most, but not all, are square or rectangular in shape. But some are trapezoidal in order to make the best use of available space. Also, some are mounted vertically, some horizontally, and some at an angle. Some may even be found in a tray similar to the CD-ROM tray in a computer where you simply slide the tray out, replace the air filter element, and slide the tray back in.

Just to make things even more interesting, some air filter elements in newer cars are not of the flat panel type, but may be cylindrical or conical in shape. In nearly every instance this shape is dictated by the car maker in consideration of the space available under the hood, however the replacement procedure is usually straightforward.

Once you’ve located and gained access to the old air filter, the actual replacement couldn’t be simpler, says our Purolator spokesman. Just lift out the old filter, noting the orientation (top and bottom, front and back) to facilitate installation of the new filter. Then wipe out the housing with a clean, damp rag, properly orient the new filter, and replace the housing and retaining clips or hardware.

“The cost of a new air filter is modest,” explains O'Dowd, “so we find that most professionals and DIYers opt for our premium PureONE air filter which is 99.5 percent efficient and has twice the capacity of conventional air filters. Obviously the labor is no more complex to install a premium filter, and the job is well within the capability of nearly every do-it-yourselfer, so there’s little reason to install anything less than the best filter available.”

“Plus, there’s much help available,” continues O'Dowd. “Your local repair shop technician can quickly and easily point out the location and procedure for replacing your air filter, as will the parts professional at your local auto parts store.”

“Furthermore,” said O'Dowd, “We invite DIYers and professionals to ask any filter-related questions of our Purolator Response Office – the Purolator PROs. Our PROs are available through our Web site,, and can answer virtually any automotive filter-related question, from application and interchange questions to inquiries regarding product features or installation and/or troubleshooting. They answer most questions within 48 hours and are available to anyone free of charge.”

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