Dirty Oil? Maybe Your Engine Air Filter's To Blame

Wait a minute. The author meant to say, ‘oil filter’ you’re probably telling yourself. No, we really meant ‘engine air filter.’ If your car’s engine air filter is torn or clogged, your engine is probably running on dirty oil.

Think about it. A vehicle ingests about 10,000 gallons of air to burn a single gallon of fuel. And if you add to it all the contaminants that the air along roads and highways contains – soot, dust, debris, leaves, straw, tiny bits of rubber – imagine the amount of dirt that can enter the engine compartment each time you take your vehicle out,

“Dirt found alongside roads is of the worst kind,” said Kevin O'Dowd, Director of Marketing & Communications for MANN+HUMMEL Purolator, manufacturer and supplier of automotive filters to the North American aftermarket. (www.purolatorautofilters.com) “It’s abrasive and full of grit and when a large quantity of unfiltered roadside air enters the engine compartment, besides contaminating the oil, it has the greater potential to damage critical engine components like valves, piston rings and cylinder walls,” O'Dowd said.

“That’s the bigger risk – both mechanically and, ultimately, financially. A torn or clogged engine air filter, can compromise a car’s performance and long life, and possibly call for the cost of replacing the engine,” he said.

When considering an engine air filter replacement for your vehicle, the two most important criteria to consider are ‘capacity’ and ‘efficiency.’ Capacity is the amount of dirt the filter can hold before it begins to restrict the flow of air and efficiency describes how well it captures the dirt before it can enter the engine’s combustion chambers.

“Modern engines are built to be more fuel-efficient and have smaller orifices and tighter tolerances. This calls for engine air filters that can trap even the smallest particles of dirt preventing them from entering the system,” O'Dowd said.

That is why ‘capacity’ and ‘efficiency’ are two of the most important criteria in determining the quality of an engine air filter. For instance, Purolator’s PureONE engine air filter’s oil-wetted, high-capacity media offers up to twice the capacity of conventional filters to trap contaminants smaller than the size of a grain of sand and is 99.5 percent efficient. This means it traps 99.5 percent of particles 200 microns in size or larger. To clarify, one micron is a millionth of a meter. Likewise, Purolator Classic air filter’s multi-fiber, high-density media traps 96.5 percent of such contaminants.

Also important to consider is the design and construction of the filter. The media in a panel-type filter is attached to a binding so it can hold its shape. If the adhesive used to attach the media to the binding framework is of inferior quality, it may melt or soften due to high under-hood temperatures. This may cause the media to pull away leaving a gap that will allow unfiltered air to enter the engine and do damage. Or, if the air filter begins to get clogged, the engine vacuum can suck in the media, causing it to rupture and once again allow unfiltered air to bypass and enter the engine.

Changing your car’s engine air filter is quick, easy and inexpensive. Older cars often had a round air filter resting in a round housing under a lid held in place by a wing nut. Today’s more advanced fuel-injected engines normally use a flat, rectangular panel-type air filter that resides in black plastic duct work in the engine compartment. Usually, all you need to do is release several clamps, separate the housing halves, lift out the old filter, and install the new one. It’s usually that simple, O'Dowd said. And your local mechanic or parts store counterman should be happy to show you where your air filter is located.

Most people should change their vehicle’s engine air filter once a year or every 12,000 miles unless you’re driving in unusually dirty or dusty conditions, said O'Dowd. Because of the long intervals between changes it’s important to install the best filter possible for reliable and efficient filtering.

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