How To Diagnose A Failing Engine Air Filter

If you look under the hood near the front of the engine compartment, you’ll find a rectangular cold air collector box. Inside is the engine air filter.

The engine air filter will get too dirty to function properly after 15K-30K miles. As a result, the engine won’t get an adequate airflow. That leads to reduced fuel economy (usually by a few MPG) and the possibility of rogue dirt and debris entering the engine and damaging some internal engine parts. In fact, you'll prolong the engine's lifespan and save up to 100 gallons of gas every year by changing the engine air filter regularly.

It’s common to change the air filter every other time you change the oil in your car. However, sometimes the air filter will get dirty sooner than usual, especially if you live in a rural or dusty area.

Telltale Signs of a Dirty Air Filter

New engine filter

Most people don’t check their air filter between oil changes, but sometimes it’s necessary. Modern fuel injected vehicles tolerate a dirty air filter better than older cars. On a fuel injected vehicle, you may notice some of the following symptoms:

  • Reduced fuel economy
  • Service engine light coming on
  • Less power when accelerating

Older carbureted engines can have more severe symptoms:

  • Misfiring engine
  • Black smoke coming out of the exhaust
  • Smell of fuel from the exhaust
  • Stumbling under acceleration

If you notice any of these signs in your car, we have good news: it only takes a few minutes to check your air filter. You don’t even need any special tools to do it.

Removing the Air Filter

To remove the air filter from the engine compartment, take the following steps:

  1. Open the hood.
  2. Locate the cold air collector box. It's a black plastic box that's located either atop or on the side of the engine. For example, it's located on the left side of the engine in a 2013 Dodge Caravan. If you're not sure where it's located, check the owner's manual.
  3. Remove the fasteners around the edge of the cold air collector box.
  4. Lift up the cold air collector box  and the air filter housing.
  5. Remove the air filter.

Identifying a Dirty Air Filter

If the air filter has been in the engine for a while, then it will be dirty. The trick is knowing if it's too dirty. When you have the air filter in your hands, hold it up to the sun or a bright light. If there's light shining through the filter, then the filter is still OK to use.

If there's no light shining through the air filter, try to shake some of the dirt loose. The best way to do this is to gently tap the air filter on the floor bottom-side down. Do NOT blow through it because doing so can damage the filter. If the filter is still too dirty to see through, then it's no longer good and you need a new one.

Replacing the Air Filter

If your air filter is too dirty, all you have to do is to buy a new air filter and then replace the old one with it. The process is the same as the steps listed above, only you'll be putting in a new air filter after taking out the old one.

If you're looking for a high-quality replacement air filter, you can get a genuine OEM engine air filter from us at a deeply discounted price.

Got any questions about checking or replacing your air filter? Need some assistance finding the right part number? We're here to help you!