What Is the Engine Air Filter?
An engine air filter, otherwise known more simply as a car air filter, is a crucial part of the functioning of your car. It filters the air that goes into your engine to ensure that only clean air can enter, and thus the engine isn’t damaged by debris, dirt, and dust. Replacing your car’s engine air filter is one of the easiest and most affordable ways to take care of your vehicle, prolonging the life and improving the functionality of your engine.
An air filter won’t work correctly if you go too long without changing it. Once it becomes clogged up with debris, this can shorten your engine’s lifespan, causing it to work less efficiently, while creating all kinds of problems that are easy to avoid if you just perform this essential piece of maintenance regularly. We’ll talk a bit more about how often you should change it later in this article.
Where Do You Find the Air Filter?
Locating the air filter won’t be an identical process for every car, but we can give general guidelines that will help. In most cases, the air filter will be situated inside a black plastic casing either at the top of the engine toward the center or over to one side of the engine. The casing will most likely be the largest piece of equipment visible under the hood that isn’t made of metal, but typically out of black plastic, so that’s another feature to keep an eye out for.
How Often Should You Change Your Engine Air Filter?
Need to know how to tell if your car air filter needs replacing? There are two primary ways to decide how often to change it.
The first is time- and/or mileage-based. Your car’s manual should include specific guidelines regarding the intervals of months or miles when you should change the air filter. But just in case you don’t have access to that information or it was somehow omitted from the manual, on average, the air filter should be replaced for every 12,000 miles you drive, or every 12 months (whichever occurs sooner). You should change the engine air filter even more often if you live in a particularly dusty location.
The second is based on looking at the filter itself and doing a “light test.” First, see our step-by-step guide to changing your air filter below for an explanation of how to remove your car’s current air filter. You’ll see whether it looks especially dirty or clean, but you might be surprised to learn that simply looking at it isn’t enough to gauge whether it should be replaced.
According to the automobile experts at AAA, “Visible dirt on the filter surface is not a good indicator. Air filters actually do a better job of trapping contaminants once they have been in operation long enough to gain a light coating of dust and dirt.” Instead, they recommend a more fine-tuned method for checking pleated paper filters: a light test. They write, “To test an engine air filter, remove it from its housing and hold it up to a bright light such as a 100-watt bulb. If light passes easily through more than half of the filter, it can be returned to service.”
Note that this light test won’t work well on extended life engine air filters that use a denser fabric for their filtering media. AAA recommends, “Unless a filter of this type is visibly caked with dirt, replace it at the mileage intervals specified by the vehicle manufacturer.”
Finally, some cars (mainly pickup trucks) make knowing when to replace your filter extremely straightforward: they include an engine air filter service indicator on the outside of the filter housing itself. How does this service indicator work? When the engine is turned on, the indicator reads the air pressure drop across the filter. As the filter gets filled with dirt and debris, the pressure drop will increase, and eventually it will reach the threshold of restricted airflow where the indicator will tell you it’s time to change the filter.
How To Change Engine Air Filter (Step by Step)
Here’s a detailed, step-by-step explanation of how to change engine air filter:
1. Park your vehicle in a safe, clean spot and pop the hood
The first step of how to change the air filter inside your car is to find a spot where you can park your car that’s both flat and dry (as well as shady, if possible, so you don’t overheat halfway through the process!). Ideally, you should also clear away excess dirt and debris from your work area (you can even use a tool like a vacuum cleaner or a leaf blower) to minimize the amount of debris that ends up in your new air filter. Then, pop open your car’s hood and ensure it’s securely held in the open position.
Now that the hood is open, give your engine a few minutes to cool off a bit. This is an optimal time to gather the supplies you’ll need, which is the next step.
2. Gather up all necessary supplies
Luckily, when it comes to changing an engine air filter, the list of supplies you’ll need to do so is relatively short (and you may not even need all of them, depending on the kind of air filter casing you’re working with):
- A butter knife
- A medium-sized standard screwdriver
- A medium-sized Phillips screwdriver
- A new, replacement engine air filter
3. Find the air filter and open up the casing
We’ve already explained how to find the air filter under the hood of your car (in the “Where Do You Find the Air Filter?” section above). Once you’ve successfully located it, the next step is to open the air filter casing up. With this, too, there are a number of different methods for opening the air filter housing depending on the style.
Sometimes the casing is held together with metal clamps that you can remove using just your hands. In other cases, there will be metal clips that you can pry away using a flat-head screwdriver or butter knife. And in still other cases, you might see that the housing is held together with screws, in which case you’ll need a screwdriver to open it up.
Older cars and trucks might even have a completely different style of air filter housing: a circular air filter enclosed in a circular metal casing that sits on top of the engine, which can generally be opened up by unscrewing just one wing nut.
4. Take out the old air filter
Once you’ve found the air filter, you’ll probably notice that it’s a color like white or yellow that makes it easy to see all the debris that the filter has collected. When removing the filter, take note of how the filter goes into the casing, so you can do the same thing yourself when you put in the new one.
5. Install your new air filter
Finally, it’s time to place the new air filter inside the housing, using the same orientation as the old filter (this is why we told you to take note of how the filter was situated in the casing as you removed it). Close up the housing and replicate the way it was secured before you opened it up, making sure everything fits together snugly and none of the pieces are wobbling around.
Now you know exactly how to change the air filter inside your car in just a few minutes! Being able to perform this bit of easy maintenance yourself can save you money (roughly $10 to $15 depending on how much your local mechanic charges for the labor of changing the air filter) while helping keep your car’s engine in tip-top condition.
How Much Does It Cost to Replace An Engine Air Filter?
If you’re researching engine air filter replacement, you may be wondering specifically about the cost of replacing your car air filter. Most engine air filters cost about $10 to $13, but this will vary depending on the make and model of your car and on the type of air filter it uses.
If you have this done at the mechanic, they might charge about $20 to $25 total for this incredibly quick and easy task that requires no special tools. This is probably why you’re looking up how to change an engine air filter yourself–you know that it’s one simple way you can save a few bucks (roughly $10 to $15 per filter change) on car maintenance.
The Best Engine Air Filters to Buy
Ready to purchase a new air filter for your car? One of the easiest ways to find the brands of air filters that will be compatible with your car’s make and model is by using Amazon’s “Filter by your vehicle” feature. You’ll be presented with only products that will work with your specific type of car, saving you the hassle of researching individual products to see if they’ll be the right fit. It’s a majorly valuable tool!
1. K&N Engine Air Filter: High Performance, Washable, Replacement Filter
This brand of air filter is a standout because it uses oiled cotton gauze filter media, as opposed to more commonly used materials like synthetic fiber or cellulose. Interestingly, K&N filters can also be washed and re-oiled rather than disposed of when they fill up with debris. The brand itself has existed for more than half a century and has a reputation for quality. Although you’ll pay more up front for their products than you likely will for most other brands, the long-term savings are absolutely worth it.
2. Fram Engine Air Filters
You might want to choose these engine air filters if you’re looking for products that are quite affordable while also providing quality and reliability. Depending on which product you buy, Fram’s filters are made of synthetic fiber or pleated cellulose, which are the most widely-used materials for filter media. The warranty period for their filters is equal to the factory-recommended air filter service interval for your particular vehicle make and model.
3. WIX Filters – 49065 Air Filter Panel
WIX is another brand that comes highly recommended by automobile experts. One of the features that makes WIX engine air filters superior to other options is the fact that they have more pleats than almost any other brand on the market. With more pleats, they’re able to filter more effectively, helping preserve your car’s engine and maximizing your vehicle’s overall performance as well as its efficiency.