How often do air filters, oil filters and fuel filters need to be changed?

How often do air filters, oil filters and fuel filters need to be changed?

A recent Car Car Council survey found that 23 percent of vehicles inspected (nearly one out of four!) had a dirty air filter that was overdue for replacement.

A. As often as necessary to prevent them from clogging. The engine management system can compensate for a dirty air filter up to a point, but when the restriction becomes too great, engine performance and fuel economy will suffer.

A recent Car Car Council survey found that 23 percent of vehicles inspected (nearly one out of four!) had a dirty air filter that was overdue for replacement.

The factory recommended service intervals for air filters tend to be overly optimistic, with many in the 30,000-to-50,000 mile range. The life of any air filter depends on driving conditions, how much dirt the filter is exposed to, and the design of the filter itself.

Some air filters have greater “depth” and holding capacity to extend filter life. The trick is to design the filter so that it is both high-efficiency, but does not clog up too quickly or become too restrictive. A filter’s efficiency depends on the media used. Most pleated paper air filters are made of cellulose and/or synthetic fibers. The size and distribution of the fibers determines the filter’s ability to trap dirt, the amount of dirt it can hold and the amount of restriction it creates to the incoming air. Better-quality filters may be treated to make them water-resistant. Rain and road splash can sometimes enter the air filter housing where it can make untreated paper filter media swell and deteriorate.

The air filter should always be checked when the oil is changed or when other maintenance is performed. Tapping or blowing out a dirty air filter doesn’t really do much to unclog it because the smallest particles will remain embedded in the media where they are likely restricting airflow. Holding a bright shop light behind the filter element is the best way to inspect it.

Q. How often should fuel filters be replaced?

A. Most late-model vehicles have no factory-recommended service for the fuel filter because the filter is a “lifetime” filter part of the fuel pump assembly buried inside the gas tank. So the only recommendation is to replace it if it is clogged or the fuel pump is being replaced. New fuel pump modules usually come with a new filter as part of the assembly, but if a customer is replacing the pump separately he should also change the filter and pickup screen.

On vehicles that have inline fuel filters, there may be a recommended service interval (typically 50,000 miles). But if the filter becomes clogged with dirt, rust or sediment from the fuel tank, it may have to be replaced sooner. Frequent fuel filter clogging would tell you the fuel tank is being contaminated with outside dirt, or it is rusting (a steel tank), or is flaking (older plastic tank). The fix here may require cleaning or replacing the fuel tank.

A common symptom of a clogged fuel filter is loss of high-speed power caused by a restriction in fuel flow when engine demand is high. If the filter becomes completely blocked, it will starve the engine for fuel causing the engine to die. Technicians will often cut open a clogged fuel filter to find out what caused it to clog up.

You May Also Like

Common Causes of Oil Leaks

Generally speaking, there are only a few common causes for the majority of oil leaks on the road.

Pick a parking lot, any parking lot, and you can tell what spaces get used the most by the number of oil spots. It’s easy to think of it as just a mess, but the unfortunate reality is it’s a bigger cause of pollution than meets the eye.

Turbochargers and GDI: A Winning Combination

Automakers have turned to turbochargers and GDI to boost fuel economy and horsepower – with less displacement.

Decoding Honda’s VINs

The automaker’s engineering prowess isn’t necessarily on display in its VIN encoding.

Staying Comfortable Behind the Counter

Ergonomics can play a big role in your on-the-job comfort and overall health.

Auto Parts Manufacturers Share Their Perspectives

Chloe Hung, Eric Luftig, Michael Kitching, Eric Sills and Matt Roney discuss what’s top of mind for their businesses.

Other Posts

A Closer Look at Crankshafts

With the great power of the engine comes the great responsibility of the crankshaft.

Spring Cleaning and Seasonal Stocking

Before the public comes calling for their spring cleanup needs, this is the perfect time to take care of our own.

Ball Joints: How Much Play Is Too Much?

There’s a common misconception that any play in a ball joint means it’s
wearing out.

Selling Tools for Underhood Repairs

The category is spread across several vehicle systems, and includes a number of specialty tools.