How to Identify a Dirty Air Filter and Know When to Replace It

A clean air filter is essential for the proper functioning of your car's engine. It helps the engine receive the right amount of air for maximum performance and efficiency. Knowing when to change the air filter is important, as a clogged filter can cause the vehicle's engine to malfunction, with less power and slow acceleration. The easiest way to spot a filter that needs to be changed is to take a look at it.

A clean, fresh filter will mostly be white, but it will darken as dust and dirt accumulate. If the filter looks very dark and dirty, it might be time to change it. If you're not sure about something, you can ask a technician to check the filters for you. When you check the filter at home, you should know that the air filter in your car looks similar to the one in your home. It is usually square and has folding lines.

A new air filter is white or off-white, while a clogged one will look darker, almost gray. When the filter looks dark and covered with dirt and debris, you should replace it as soon as possible. If you know where the air filter is located (you can check the owner's manual to find out where to look), you can perform a visual inspection. If the air filter is clean, it must be white or whitish. Over time, as dust and dirt accumulate in it, the air filter will darken and the dirt will be noticeable.

When it starts to look dark and dirty, you may need to change it. The filter provides clean air to the engine, so it can receive the right amount of air for maximum performance and efficiency. If the filter is clogged and not enough air enters the engine, the light can come on automatically. It is located under the hood of the car and in the engine air filter housing, usually on the top or next to the engine. So how do you know when to change it? It's generally recommended to change your air filters every 10,000 to 15,000 miles, more or less. When you can replace them in your home, you'll be moving towards cleaner air in every room.

A clean air filter will help the engine work better; in newer cars, it can increase acceleration by up to 11%, and in older cars it can improve mileage by up to 14%. A good sign that the air filter needs to be replaced is black smoke coming out of exhaust pipes when starting up. If you're driving in heavy traffic on a regular basis, your air filter won't last as long. Air flows through the engine through an air filter which prevents leaves, dust, dirt and other contaminants from entering. If any of these signs are present or if you have had the same filter in place for a long time, it is advisable to visit your local dealer for a replacement. Some newer car models have changed engine design for better use of space which sometimes means placing air filters in hard-to-reach places which can slow down replacement process.

Knowing some of these telltale signs of a dirty or clogged filter can help avoid having to wait too long for a change.

Simon Genz
Simon Genz

Infuriatingly humble social media practitioner. Incurable communicator. Friendly internet trailblazer. Zombie fan. Lifelong foodaholic.