Here’s What Can Happen When Your Car’s Engine Air Filter is Dirty

Written by

Mia Bevacqua, ASE Certified Master Automobile Technician

Automotive Subject Matter Expert at CarParts.com

Updated on March 5th, 2024

Reading Time: 4 minutes
Summary
  • The air filter traps contaminants within its fibers to prevent dirt from entering the engine.
  • Some effects of a dirty air filter include poor engine performance, increased fuel consumption, and increased tailpipe emissions.
  • The frequency in which you should clean the air filter depends on what’s indicated on the vehicle manufacturer’s service schedule.

Replacing an air filter is typically one of the easiest car care tasks. Usually, all you need to do is remove the airbox lid by releasing a few clips or undoing a few screws, and the air filter can be popped right out—it’s that easy.

Since most air filters are also relatively inexpensive, it’s a good idea to change your car’s filter regularly. When left unchecked, a dirty air filter can lead to various problems that make your vehicle less efficient and less enjoyable to drive.

What Does an Engine Air Filter Do?

Your car’s air filter traps contaminants within its fibers to prevent dirt and debris from entering the engine. The air filter also promotes clean airflow into the air intake system.

The air filter is located downstream from the engine, inside a housing that’s attached to the air intake tube. When the engine is running, the pistons move downward in the cylinders, creating a vacuum that pulls air through the air filter and into the engine. That air mixes with fuel and is then ignited, creating the energy to propel your car.

Your car’s air filter traps contaminants within its fibers to prevent dirt and debris from entering the engine.

What Can Happen When Your Engine Air Filter Is Dirty?

Today’s computer-controlled vehicles use sensors to measure the amount of air entering the engine. Because of this, a dirty air filter has less of an effect on engine performance than it did in the past.

The computer can compensate for a dirty air filter—but only up to a point. When the filter becomes completely clogged (or close to it), there simply isn’t enough airflow to keep the engine running properly.

An air filter that’s seriously neglected can result in several problems, including:

Poor Engine Performance

A severely restricted air filter can starve your engine of air, causing performance problems, such as poor acceleration and rough running.

Turbocharged engines, which require an unobstructed air intake to build proper boost pressure, often suffer the most from a clogged air filter. Vintage vehicles with a carburetor are also prone to performance problems caused by a restricted air filter.

A dirty air filter can lead to increased fuel consumption.

Increased Fuel Consumption

The engine has to work harder than normal to pull air in through a dirty air filter. That rise in energy expenditure often leads to an increase in fuel consumption.

Increased Tailpipe Emissions

In extreme cases, a dirty air filter can reduce engine airflow enough to create a rich running condition (too much fuel; not enough air). As a result, the engine will produce a greater amount of tailpipe emissions.

Illuminated Dashboard Warnings

Some late-model vehicles are equipped with an air filter life monitor that uses various sensors to detect a dirty air filter. A computer (often referred to as the powertrain control module), receives data from those sensors.

When the module determines the air filter requires replacement, it turns on a warning light on the dashboard, reminding the driver to replace the air filter. In some extreme cases, a dirty air filter (and the resulting engine performance problems) may also cause the module to turn on the check engine light.

If your filter sees severe use, check it every 6 months/6,000 miles and replace it if it looks dirty.

How Often Should You Change Your Car’s Air Filter?

You can approximate how often your car’s air filter should be changed by consulting the vehicle manufacturer’s service schedule. The information can be found in your owner’s manual or supplemental service booklet.

But if you regularly drive through a dirty or dusty environment (e.g., dirt roads), you may need to change the filter more frequently than the vehicle manufacturer recommends. If your filter sees severe use, check it every 6 months/6,000 miles and replace it if it looks dirty. You’ll know it’s time for replacement when the filter element is dark and allows very little light to pass through.

Check out these tutorial videos on how to replace your air filter:

Need to Replace Your Vehicle’s Air Filter? Get a Replacement Online

You shouldn’t hesitate to replace a clogged air filter because it can cause your engine to have poor performance and increased fuel consumption. Luckily, replacing your vehicle’s air filter is a relatively easy task. Need a replacement air filter? CarParts.com is a one-stop shop for replacement parts like air filters.

You can be confident that we carry an air filter that can fit your vehicle because CarParts.com has a wide selection of air filters. We source our catalog from the most reputable aftermarket brands, so you can trust that our available air filters will provide good airflow and filtration. To guarantee part fit, just  enter your vehicle’s year, make, and model into our vehicle selector to see a list of compatible parts.

Shopping for a replacement air filter doesn’t need to break the bank. Shop for affordable air filters from CarParts.com today!

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.