One of the most expensive maintenance items for your car just happens to be among the most crucial. Your car’s engine air filter allows a fresh flow of vital oxygen to mix with fuel in the intake that subsequently burns, unlocking energy that spins the engine and sends power to your wheels. One simple component can be the difference to ensure you’re driving a clean-burning, fuel-efficient, and reliable car.
Like many vehicle components, the air filter is a part involved in your routine maintenance schedule. How do you know it’s time to replace your air filter? Here are some common symptoms of a dirty air filter and how you can tell it needs to be replaced.
Symptoms of a dirty air filter
If you put your hand over your mouth, even with your fingers spread, you can tell the difference in the air volume you’re able to breathe in. If you try the same motion after running a mile, it’ll be way harder to catch your breath with your mouth partially covered. The same goes for your engine when it tries to draw in air—things just don’t work properly.
How can you tell when an air filter is dirty? It could be time to change the air filter if you experience:
Decreased fuel efficiency. If your engine can’t draw in enough air to burn efficiently, more fuel is injected to try to compensate for it. A new air filter can increase fuel mileage.
An illuminated Check Engine Light. If an air filter is clogged and restrictive, the diagnostic system might think there’s a problem metering the air intake, or a cylinder misfire might be discovered.
Reduced performance. Since the engine can’t unlock the energy that comes from burning oxygen in the air, less power is produced with every piston stroke.
A gas odor when starting the engine. The engine may nearly flood trying to start with less air present, and the smell of raw fuel may be present for a bit.
A visibly dirty air filter. That’s right, if your air filter looks dirty when you inspect it, you should probably swap it out for a new one.
Normal service interval for an engine air filter
How often should you change the engine air filter? Each manufacturer specifies the inspection and replacement interval in the recommended services schedule, and it can vary from vehicle to vehicle. At minimum, the air filter should be inspected every time you change the engine oil, or at least once per year.
It’s common for an air filter to need to be replaced every 12 months or 12,000 miles. If you drive on gravel roads frequently or your engine idles for a long time, it can become clogged sooner. Change it out when you can’t see light through the pleats in the filter.
Check these items at the same time
If your air filter needs to be replaced, it’s a good idea to perform a multi-point visual vehicle inspection at the same time to make sure you don’t experience unexpected trip interruptions. Inspect the following items:
- Check the engine oil level and condition. Change the oil and filter if it’s dark or contaminated.
- Check the rest of the fluids under the hood for the appropriate level and condition.
- Inspect the tire tread. Have tires replaced when they’re under 2/32nds of an inch tread remaining.
- Check the tire pressure and inflate them to the tire pressure indicated on the driver’s door placard.
- Inspect all the exterior lights, including headlights, taillights, turn signals, and marker lights for proper operation.