How do I know if my air filter is bad?

08 Apr.,2024

 

Posted on May 22nd 2018

If the engine of a vehicle is its heart, the air intake is the lungs. When we breathe in air, we deliver life-giving oxygen to our entire bodies. Just as we need oxygen to live, so do our vehicles- but what happens when a dirty air filter blocks that necessary oxygen out?

Combustion engines rely on air to function, and a bad air filter can suffocate a vehicle. This can lead to extensive problems down the road. Luckily, dirty air filter symptoms are easy to identify once you know what to look for.

Read on to learn the signs your vehicle needs air filter maintenance, so you can keep it healthy and on the road for years to come!

1. Air Filter Appears Dirty

One of the easiest symptoms to recognize is the appearance of the filter itself. Brand new filters appear nearly white. Over time, contaminants in the air will dirty your filter and turn it brown or black.

A visual inspection can be your first confirmation of a bad filter. Always examine your filter under adequate light. If it appears contaminated with dirt, dust, and debris, it could be time to clean it out.

2. Decreasing Gas Mileage

A decrease in gas mileage is usually a sign that something is amiss. Your air filter contributes to your fuel efficiency, but a dirty filter can cause reduced oxygen flow. A vehicle must make up for this by burning more fuel to compensate.

A clean air filter keeps the air flowing, and keeps your fuel economy right where it should be.

2. Your Engine Misses or Misfires

Does your car have a hard time starting? Do you have to make multiple attempts or rev the engine to get it going? If your car has trouble turning over, it could have a low air to fuel ratio.

When the ratio is too rich with fuel, it can cause engine flooding and spark plug pollution. This can result in misfires or trouble starting. If you've got a rough idle or a reluctant start, the air filter is the first place you should check.

3. Strange Engine Noises

When your car is in park, what does it sound like? An engine that has a good oxygen flow should have a smooth and even purr. If your idle is rattly, or you hear a vibration or hiccup, you could be facing a bad air filter.

A common culprit of this issue is polluted spark plugs from air intake issues. If you discover your air filter is in need of a change, it's wise to also check the condition of the spark plugs to see if they have suffered any damage as well. Replacing these two parts can help your engine idle much smoother.

4. Check Engine Light Comes On

Your check engine light can illuminate for many reasons, one of which is deposits in the engine. When impurities get inside, it can cause a buildup over time that triggers the service light once it starts having an impact on engine performance.

For every gallon of gasoline consumed by a car, it must be able to intake thousands of gallons of air to process that fuel efficiently. Combustion engines can't function without an essential component- air!

If your check engine light comes on, you should have it read right away to identify the culprit. A professional can read your service code and help you determine if it is related to air intake issues.

6. Reduction in Horsepower

If your acceleration seems sluggish, your horsepower could be suffering from oxygen deprivation. If your car jerks when accelerating or responds slower than normal, chances are it's not getting the air it needs to function at peak performance.

Horsepower in a vehicle is completely dependant on how well the engine functions. The engine is fighting harder by dumping more fuel to keep up with the reduced oxygen. That power being diverted will decrease your horsepower significantly.

7. Flames or Black Smoke from Exhaust Pipe

When oxygen struggles to reach the engine, fuel may not be burning off at an adequate rate. This can result in some of the fuel leaking through the system and out of your exhaust pipe. You may also hear popping sounds as super-heated fuel is expelled through your exhaust system.

This issue wastes fuel and can be very dangerous to your vehicle and the environment. Make sure to check into any unusual exhaust emissions.

8. Strong Fuel Smell

When gasoline is leaking from the exhaust pipe, it will have that telltale smell to notify you that something is off. While a smell can indicate a fuel tank leak as well, you can confirm your suspicions of exhaust leakage by checking for the signs of black smoke.

Dirty Air Filter Symptoms Are an Easy Fix

All the parts in a car work in harmony with one another. When one piece is malfunctioning, you'll see a chain reaction of issues building from one system to the next.

Something as simple as the air filter can cause everything from harmful emissions, wasted fuel, damaged spark plugs, and engine buildup. That's why it's smart to keep an eye on parts that suffer a lot of wear and tear.

When you notice dirty air filter symptoms, don't worry. It's an easy and relatively inexpensive fix. As long as you keep your filter clean and maintained, you'll prevent some of these easily avoidable issues and extend the life of your vehicle.

Need tips on how to change and clean your air filter? Visit us at Air Filter Blaster!

3 Signs of a Dirty Air Filter

Yes, a dirty and clogged air filter can impact your engine's health and performance. That's why experts recommend changing it regularly. While most manufacturers urge a change every 12,000 miles (19,300 km), certain factors can reduce this lifespan. To pinpoint the optimal time for a replacement, pay attention to these common issues that normally arise when you need a new engine air filter:  

 • The check engine light on the dashboard

 • Reduced fuel economy

 • Sluggish acceleration (more common in older vehicles)  

1. Check Engine Light Comes On  

The first sign that your engine air filter is clogged is when the dashboard check engine light (CEL) illuminates. The CEL warning light will turn on when the engine is not getting an adequate supply of air. If you have noticed other symptoms like lackluster acceleration or reduced fuel economy, then that light could very well be telling you the air filter might be clogged and needs to be changed.  

2. Reduced Fuel Economy  

Another common sign of a dirty air filter is reduced fuel economy. The engine is unable to pull in enough outside air for efficient combustion due to a clogged air filter. The engine then has to work harder and burn more fuel to provide the same amount of performance. If you're finding yourself at the gas station more often, it might be time to replace your air filter. Although it depends on multiple factors, it's believed that replacing a clogged engine air filter can improve your car's gas mileage by as much as 10%.  

3. Sluggish Acceleration  

If you leave the check engine light on for too long, you will experience reduced engine performance due to a clogged air filter. This is especially the case with older vehicles. Airflow restriction caused by a dirty filter can strain engine components and lead to poor combustion. So, what happens? Your engine compensates by using more fuel to create the same amount of power. This is not only inefficient, but it also means you will notice reduced acceleration and less horsepower.  

Why Engine Air Filter Should Not Be Inspected Unless Replaced

Some people advise performing a visual inspection and manually checking if the engine air filter is dirty. However, if the reason for your check engine light (CEL) is a suspected dirty air filter, then the filter should be changed. A great deal of effort must be exercised if the decision is made to inspect a used air filter since there is a danger of introducing contamination to the engine side of the filter. This contamination could then be pulled into the engine unobstructed, causing potential harm. For this reason, it is suggested that if the air filter is removed even for inspection, it should be replaced. Replacing your engine's air filter is a relatively simple operation and can be performed with basic hand tools.  

How a Dirty Air Filter Affects Your Car Performance  

Just like a clean engine air filter will help optimize emissions as well as improve acceleration and fuel economy, a dirty filter can lead to:  

Damaged Spark Plugs: Driving with a clogged air filter for too long can cause an excess of unburnt fuel, leading to carbon deposits on your spark plugs. This, in turn, can cause misfires, rough idling, and difficulties starting the engine.

Reduced Engine Performance: The restricted airflow can lessen the engine's power. However, when you start seeing loss of power and sluggish acceleration from a clogged air filter, there's going to be a check engine light already illuminated on the dashboard.

Engine Damage: The worst-case scenario is that a very dirty air filter allows dirt and particulates into the engine, causing substantial wear and tear over time.

Increased Emissions: Due to incomplete combustion from lack of air, your vehicle might release more pollutants, affecting air quality and potentially failing emission tests.  

To protect your engine, it is essential you prioritize preventative maintenance schedules according to your car's owner's manual. This includes performing regular check-ups to avoid unexpected issues. If you're driving under normal driving conditions, such as commuting in the city or highway driving, you can follow the standard maintenance schedule. However, if you frequently drive in challenging conditions, like dusty roads, it's best to follow the severe maintenance schedule in your car's owner's manual.  

Choosing a high-quality filter, such as the FRAM Ultra Air™, can make a significant difference. It not only lasts longer but also offers superior performance and enhanced engine protection compared to standard filters. If you're uncertain about the best engine air filter for your car, visit fram.com, and we will guide you through the selection process.

How do I know if my air filter is bad?

Dirty Air Filter Symptoms: 3 Signs Your Engine's Air Filter is Clogged