What Does Your Vehicle's Oil Filter Do?

Your engine needs constant lubrication to prevent friction and heat from climbing past tolerable levels. That lubrication comes in the form of motor oil. Over time, the oil in your car's engine will accumulate dirt, debris, and particles. If these elements gain access to your engine, they can cause damage and early wear and tear. The obstacle that stands in their way is your oil filter (O.F.).

Motor oil is sent from your oil pump to your vehicle's crankshaft, valvetrain, and other components. On its way, it passes through the filter. It leaves behind the dirt and particles that have accumulated since the last time you changed the oil. However, if the O.F. does its job properly, it will continue to collect debris to the point of becoming clogged. Once that happens, you'll need to replace it.

A Built-In Safety Measure

A clogged O.F. implies that your engine would be prevented from receiving the oil it needs for lubrication. Because a lack of lubrication can quickly lead to expensive damage, such a circumstance would be problematic. For this reason, oil filter manufacturers design their product with a bypass valve. It is a safety measure.

If a predefined level of pressure is detected in the O.F., a valve opens to allow the passage of oil. Unfortunately, the oil that passes through the valve does not go through a filtering mechanism. Any dirt, debris, and particles present are allowed to enter your engine.

Because clogs are not visible, it's often difficult to know when your O.F. needs to be changed. You should refer to your owner's manual for the recommended interval. However, a lot of mechanics will recommend that you replace the component with an OEM oil filter whenever you change your oil.

Selecting A Replacement

When choosing a replacement, you'll need to consider its filtering capacity, thread size, and other factors that influence its ability to protect your vehicle's engine. Some units come with as much as 40-50% more filtering material than lower-priced alternatives.

Other considerations include the size of the holes, whether the filter is a side-mount, and whether your vehicle needs an anti-drainback system. This latter feature is commonly required for overhead cam configurations. It prevents the oil from draining out of the filter when you turn your car off.

An Inexpensive Insurance Policy

The reason mechanics suggest replacing your O.F. every time you change your oil is not because they're looking for the sale. Oil filters usually cost less than $15, so there's very little profit in it for them. Rather, they do so because it is an inexpensive insurance policy on the health of your car's engine. By keeping dirt and particles from reaching it, the product offers valuable protection while ensuring your engine receives the lubrication it needs.

Given that an OEM oil filter costs so little, your mechanic may be correct.