What Happens if You Don’t Change Your Vehicle’s Air Filter?

A picture of a person wearing red safety gloves while replacing a vehicle's air filter.

Poor fuel economy or strange noises coming from beneath the hood of your vehicle could be the result of a number of things, including your car’s air filter. And while clean air is a necessary component of healthy living, it’s easy to neglect its importance in the life of your vehicle. In this blog, we’ll explore what happens if you don’t change your air filter, the telltale signs you need a replacement, and how often to change your air filter.

What Does an Air Filter Do?

Air filter replacements are often just as neglected as oil changes. This is partly because many drivers don’t know what their air filter does and what happens when you don’t c change your air filter. But given how important your vehicle’s air filter is, let’s explore how it contributes to the life and longevity of your vehicle.

The air filter is there to prevent dirt and debris from entering the engine and causing major issues. Without it, or without a properly functioning filter, your vehicle will experience loss of power, reduced fuel economy, and even engine failure.

If you were to head out to the local track and run a few miles, you wouldn’t get very far if your lungs weren’t working properly. The same goes for your vehicle. Think of your vehicle’s air filter as the lungs of your car. If they’re dirty or congested – making it impossible for clean air to pass through your vehicle’s system – then you’re not going to get very far. So, what happens if you don’t change your air filter? Your vehicle will eventually quit on you.

What’s the Difference Between an Air Filter and a Cabin Filter?

Most new vehicles will have four types of filters: the cabin filter, the oil filter, the fuel filter, and the air filter (sometimes called the engine filter). While some older vehicles lacked a cabin air filter, vehicles have always had an air filter to protect the engine.

If you’re not a car person, it can be difficult to understand what an air filter does, let alone the difference between the multiple types of filters. To help you get a little more information on the importance of your vehicle’s filters, we’ll briefly explore the function of each one below.

Cabin Filter

Your cabin’s air filter regulates and cleans the air inside your vehicle (your cabin) so you breathe clean air while driving. Located beneath your dashboard, the air filter prevents dust and allergens from traveling through your car’s heating and cooling system and into your cabin.

Oil Filter

A vehicle’s oil filter cycles the clean oil back through the engine parts. Since the oil itself has several purposes, including cooling the engine and lubricating essential parts so they don’t grind against each other, the oil filter’s job is to keep your vehicle running smoothly.

Fuel Filter

A fuel filter acts as an absorbent barrier that purifies the fuel of harmful contaminants before they can enter your vehicle’s fuel injection system. Without a properly functioning fuel filter, harmful dirt and debris could make it inside the engine.

Air Filter

The air filter (also known as the engine filter) is located within your engine. Like your vehicle’s cabin filter, it keeps harmful debris and dirt away from places where those pollutants shouldn’t be. In this blog, we’re focusing specifically on your vehicle’s engine air filter.

A close up, over the shoulder picture of a man wearing a leather jacket while driving.

What Happens If You Don’t Change Your Vehicle’s Air Filter?

The symptoms of a dirty air filter in a car range from evident to not so obvious. We’ll explore those in more detail below to help you better understand what happens if you don’t change your air filter.

Engine Troubles

What happens if you don’t change your air filter and it accumulates dirt? For starters, you could experience engine issues. If your vehicle is misfiring or having a difficult time starting, it may have a low air to fuel ratio. A contaminated air filter can restrict engine airflow and lead to a rich air/fuel mixture. This happens when there’s a lack of oxygen in the exhaust (what’s known as a rich condition). 

Strange Engine Noises

Do you hear unsettling noises when your vehicle is idling? If you notice coughing, popping, or spitting noises coming from your vehicle’s engine, the culprit may be a clogged air filter.

Check Engine Light

Because your vehicle’s engine performance is essentially monitored by a computer, an oxygen sensor will send a signal to the engine control module if your vehicle is experiencing abnormal conditions. As a response, your vehicle’s check engine light may come on.

Air Conditioning Issues

What does a dirty air filter do to a car? It can actually make those summer drives a whole lot hotter, as it prevents your vehicle’s air conditioning system from functioning properly. A clogged filter forces the system to work harder, which results in unnecessary wear on your vehicle’s entire system. Over time, this can weaken the power of your vehicle’s cooling system. The result? Warm or hot air on your face while driving.

Performance Problems

A dirty air filter can also result in decreased performance by as much as 10%. Since your engine needs oxygen for fuel to successfully combust, a poorly functioning air filter can restrict airflow. This can result in a loss of power, acceleration, and torque.

Your Vehicle Smells After Starting

If you smell an overwhelming scent of gas after starting your vehicle, it may be the result of an insufficient amount of air entering the fuel injection system. When the air filtering process isn’t working properly, gas may not completely burn up during the combustion process. As this happens, the unburned fuel may exit the vehicle through the tailpipe, leaving a residue of black soot behind, along with a strong petrol odor.

A picture of someone changing a vehicle's air filter while wearing black safety gloves.

Can I Visually Inspect My Vehicle’s Air Filter?

Although replacing your air filter may require the work of a trained professional, anyone can go about checking one. In most modern vehicles, the air filter is located inside a rectangular box under the hood. Some vehicles – including ones with carburetors – may have big round air filters.

Once you check underneath your hood, the air filter is typically inside a cover that you can easily open by removing snaps or clips. From there, lift the air filter out and inspect it in the light. Air filters come clean and white, so if your air filter is black or brown and caked in dirt, it’s definitely time for a replacement.

How Often Should I Change My Vehicle’s Air Filter?

Most car manufacturers recommend changing your air filter every 12,000 miles or every 12 months, whichever comes first.

While you may not think much of this small service, regular engine air filter replacements are affordable and can save you thousands of dollars in engine damage. It also helps improve your vehicle’s performance and efficiency so you save at the pump. Annual emissions inspections and annual vehicle inspections check a vehicle’s engine filter for this very reason.

Is your vehicle acting up? Whether it’s as simple as an air filter or a car trouble that needs a little more attention, each of our K&W experts can get you set up and safely back on the road. Contact us today to schedule an appointment.