What are the signs of a bad air filter?

carpart

May 03rd, 2019

What are the signs of a bad air filter?

How often should I change my air filter?

In average climate, air filters should be replaced about every 12 months or every 20,000 to 25,000 kilometres. In rural areas with a lot of dust and dirt or in cities with a fair bit of traffic, you’ll probably need to replace your air filter a bit more frequently.

If you’re not sure whether or not it’s time to go ahead and replace your air filter, there are a few ways you can tell. The following are five indicators that it’s time to change your air filter.

1. Your air filter looks dirty

It may seem like a no-brainer, but if you’ve never taken a look at your air filter before you might not know what to look for. A dirty air filter may appear to be dark in colour, either brown or black. But a new air filter is a lighter colour, closer to white. If it looks dark, it’s time to either clean your filter or swap it out for a brand new one.

You should also look at your filter to check for any other unusual contaminants or debris. Your filter shouldn’t be coated in dirt, dust, or rust.

2. You’re experiencing less fuel efficiency

You’ll experience better fuel economy with a clean and functional air filter. If it’s time to clean or replace your air filter, you might notice your car is less fuel efficient—up to 14 percent less. This specific issue effects older cars more than it effects new cars.

If your air filter is bad, fresh air will be blocked from entering the internal combustion chamber and your car will compensate by using more fuel.

3. Your car doesn’t sound quite right when you start it

Your car might make a ‘coughing’ sound when you turn it on and when it’s idling if your air filter is bad. This happens when good, clean air can’t get inside the engine. You might also notice this unusual sound when you’re hitting the brakes.

4. Your spark plugs are damaged

If you let a bad air filter go without being replaced for too long, your spark plugs can get dirty and damaged, too. This might impact how your engine functions. It’s a good idea to check your air filter if you notice your spark plugs are dirty and vice versa. You should clean both of them at the same time.

5. You’re noticing a strong smell of fuel or black smoke from your exhaust pipe

If your air filter isn’t working as it should, fuel may leak out and cause a plume of black smoke when you drive. You may also notice the smell of fuel is quite strong. These are two sure signs that something isn’t quite right, and your air filter is a likely culprit.

My air filter is bad, what should I do?

If you find out your air filter is bad, don’t worry. It’s easy to replace or clean on your own. If you want, you can find a mechanic who can help, too.

To find out more about why you should keep your air filter clean, you can read our article Will a new air filter improve my engine performance?