How to clean, check and change your air filter
There's never a good time for your car to begin showing signs that's something wrong, but especially when the engine light is illuminated. As the driving force behind your vehicle, when any component of it is faulty, it will affect performance, and — more importantly — it can impact your safety on the roads. So, you'll need to diagnose the problem and repair it as soon as possible.
One of the most common problems that could affect your engine is if your air filter is dirty or needs replacing. Whether you're a dab-hand with auto repairs or you have a little basic knowledge, it can be all too easy to forget about cleaning and checking the air filter, and it's often tricky to know when to change it. To help you, we have put together this handy guide. We will cover:
- What does an air filter do?
- How long does an air filter last?
- Can I drive without an air filter in my car?
- What are the symptoms of a faulty or clogged air filter?
- How to check your air filter
- How to clean your air filter
- How to change your air filter
Your car engine uses a mixture of oxygen and fuel to complete the combustion process, which is responsible for powering your vehicle. This means that air filters are particularly important for engine health and can typically have one of two benefits. There are long-lasting air filters, the main purpose of which is to keep the engine parts free from debris, whereas the other kind has deeper pleats to allow for increased air flow, and therefore better combustion.
There are three main types of engine air filters. The one you choose can have an impact on how often you'll need to maintain it, or whether you can clean and re-use your air filter. These include:
- Paper filters: The cheapest and most common types of air filters used nowadays. However, these are not the best choice for all cars. Rather they are better suited to small cars and driving in locations where there isn't much dust and debris. It's important to note that these aren't re-usable and have to be replaced often.
- Gauze filters: These can be washed and re-used and are available in two different types: oil gauze and synthetic dry. The oil gauze ones are most popular and need maintaining every 5000 miles. On the other hand, the synthetic ones require cleaning more often than this with a specialist solution. You will need to check a gauze filter every couple of months to see whether it's dirty and then will have to clean this. You will also need to keep them well-oiled for better performance.
- Foam filters: You're unlikely to make a repair with a foam filter as they are designed to be for much smaller engines than cars, such as lawn mowers. However, some manufacturers may place a foam wrap over the air filter to create a barrier between particles, keeping the engine clear and running smoothly.
The best way to find out how often you should change your air filter is to consult your car's manual, as this will detail how often your specific make and model of vehicle will need maintenance of the air filter. However, if you've misplaced your handbook, or have seen some contradicting information, you should generally change your air filter every 12,000–15,000 miles.
If you frequently drive in smoggy areas with lots of pollution, you are more likely to need to change your air filter sooner. This is because the dirtier the air outside, the quicker your air filter gets mucky. This can then cause breakdowns and result in seriously expensive damage. At the very least, cars that drive every so often in these polluted areas will need to have their air filters changed once a year. But, if you drive very often in these places, your filters will need changing much more frequently. If you're unsure, we recommend speaking to your car manufacturer's customer service team for specific advice about your vehicle.
The air filter keeps your engine healthy and the combustion chamber working correctly, so take out this essential part and you're very likely to do some expensive damage to your engine or fuel delivery systems. Additionally, as your engine burns more fuel to try make up for the loss of oxygen, you'll also be releasing excess toxic emissions into the atmosphere, damaging our planet and the air around you as you drive.
So, it pays to know when you have a faulty air filter so you can change it quickly, rather than removing it and carrying on without one.
Knowing when something's wrong with your air filter isn't always easy, as many of the symptoms overlap with other potential vehicle issues. But, knowing the potential signals your car may give you when there's a problem with the air filter can certainly be helpful in narrowing down the possible causes. We will be detailing some of the most common symptoms of a clogged air filter below.
Reduced fuel efficiency
Any reductions in fuel efficiency are a clear sign that something is wrong with your vehicle, more specifically that your air filter is clogged. This is because your air filter is responsible for keeping your engine free of debris and ensuring the combustion chamber has enough clean oxygen to mix with the fuel, so when it's unable to do either of these things, you're bound to see reduced fuel efficiency.
If your engine receives less oxygen flow than is needed, your engine will try burn more fuel to compensate for it, which can result in a smoking exhaust and some more severe engine problems if it's not sorted as soon as possible.
A misfiring engine
Have you noticed it's taking your engine more than one time to start working? If so, this could be down to a dirty air filter which is causing a low fuel to air ratio. If you ever find yourself with a misfiring engine, the first place you should check is the air filter.
If your engine has too much fuel inside it, this can cause flooding in the engine, as well as pollution of the spark plugs, both of which could create costly problems to repair.
There are plenty of other issues that could cause your car trouble when starting up, so ensuring you cancel out the air filter before you spend money getting everything else checked is important.
Rattling or vibrating engine
If your car seems to be making some unusual noises, it could well mean that your air filter has become clogged. When the engine has enough oxygen flowing, you'd only ever hear a smooth hum, so any noise other than this means your ignition system is being starved of oxygen.
Illuminated engine light
Our car's communication systems are very good at telling us when something is wrong, so if you see the engine light illuminated, this could be your vehicle's way of signalling an air filter problem to you.
If impurities have been allowed to pass through to the engine, it will cause a build up over time which will then trigger the engine light and you're likely to notice reduced fuel efficiency and power.
When your engine isn't functioning properly because it's being gradually starved of oxygen, you're bound to notice a reduction of power. This could mean you're accelerating and not getting very far, or your car is making jerking motions, both of which would suggest a clogged air filter.
There are many types of exhaust smoke that your car can emit, but if your engine isn't getting enough oxygen, then it's likely to be black smoke you'll see. Not only can cause this total engine breakdown, but the excess emissions are harmful to the planet, so it's important you check out your air filter immediately to prevent any damage happening.
Strong fuel smell
When your engine is overcompensating for a lack of oxygen by burning more fuel, it's very likely your car will let off a strong fuel smell. It's possible for this scent to mean you have a fuel tank leakage, but if it's also coupled with the presence of black exhaust smoke, you'll know to check your air filter.
First things first: you'll need to locate your air filter. In most, new car models you will find this inside a rectangular box known as the cold air collector box, which is close to the front of the vehicle. This is typically just near the car part that frames your wheel well in the air supply system. However, this can differ from car to car, so again, consulting your vehicle handbook is advised to find exact details.
On older cars, the air filter will be found in the air cleaner, which can be found on top of the engine. It's usually a large, round shape with a pipe attached which helps facilitate the movement of air to mix in with fuel in the combustion chamber.
There's quite a simple test for finding out if your air filter needs changing in both new and old cars. Once you locate it, you'll need to lift it out (this should be easy to do, as it's not fastened down by anything) and hold it up against a bright light. If your air filter is fine, you should be able to see through it, but if not, you'll need to try tap some of the dirt off. Although it can be tempting, don't blow on the air filter to remove dirt as this can damage it. Instead, gently tap the bottom side of it against something hard and repeat a couple of times. If you still can't see through the filter after this, it may be time to clean it. If by following the advice in the section below doesn't make your filter any clearer, you'll know it needs to be replaced instead.
If your air filter looks a bit clogged, but you don’t think it's ready for a full replacement just yet, then you'll need to make sure you give it a good clean. All you'll need to do is follow the below instructions to restore your air filter and keep it performing at its best for longer.
What you'll need:
- A clean bucket
- Laundry detergent
- A clean lint-free towel or cloth
1. Fill your bucket with clean water
2. Add a small amount (about a quarter of a capful) of laundry detergent
3. Mix the detergent and water together
4. Submerge your filter in the water and swirl it round gently
5. Use the tips of your fingers to displace any dirt or dust that may be stuck to the filter
6. Once you're satisfied with the cleanliness of the filter, remove it from the water and shake any excess liquid out
7. Place it on the lint-free towel or cloth to air dry
If you've checked your filter and found that it needs changing, you'll be pleased to hear that this is quite a simple repair that you can do yourself. Failing to change your air filter when it needs it can result in your engine producing more exhaust smoke, which in turn may cause your car to fail its MOT, as well as decreasing its fuel efficiency. So, it's important to change the air filter at the intervals recommended by the manufacturer.
To begin your repair, you'll need to make sure you have the following:
- The correct replacement filter for your car. If you have any trouble finding the correct one, we have a handy product finder tool you can use to discover the parts compatible with your exact make and model of vehicle
- A clean rag or cloth
Once you've got the equipment needed, you'll then need to follow the below steps:
1. Locate the filter: First things first, you'll need to locate your air filter. If you've already followed the steps in our check your air filter section then you'll have already found this. But, if it's your first time looking for it, be sure to read your owner's manual or research your car make and model to find out where it is.
Before you look for your filter, you'll need to ensure your engine is completely cool and your car is parked on level ground with the handbrake on to prevent any injuries or accidents.
2. Release the filter: Once you've located your air filter, you'll then need to remove it carefully according to the manufacturer's instructions. This might involve releasing catches holding it in or lifting open some components from your air filter supply system.
3. Remove the filter: Carefully lift the filter out of its compartment, paying attention to any clips you may need to undo before you can remove it.
4. Wipe down the filter housing: Get rid of any existing dirt and debris inside the engine air filter housing by taking out the compartment that holds the filter and wiping it down with a clean cloth or rag.
5. Fit the new filter: Once the housing is all dusted down, you can then put the filter compartment back and slot the new air filter in — just make sure to compare the old and new filters to make sure your replacement is definitely a perfect fit. You'll also need to check for any markings which will show you which way to put the new filter in.
Your air filter is an essential component for the smooth running of your engine, so knowing how to diagnose problems with it, as well as how often to clean, check, and change your filter is important. Here at GSF Car Parts, we have all of the car parts you'll need for maintenance and repairs of your vehicle. This includes fuel and emission parts, as well as those for your car's body and exhaust, plus many more key replacement pieces.
We offer free UK delivery on all orders over £25, as well as a handy (and free!) Click and Collect service meaning you can pick up your order from any of our branches when it's convenient for you. We even offer an unbeatable 365-day returns policy for online purchases, so you have a full year to return any unwanted bits. Planning to carry out some repairs? Be sure to check out our knowledge hub for tips and tricks for many DIY projects. This includes advice for checking, changing and charging your car battery, as well as how to remove bodywork scratches, jump start your car and much more. If you have any queries, don't hesitate to get in touch with us today.