FAQs About Your Car’s Engine Air, Fuel, and Cabin Air Filters

  • Sep 10, 2021
image of a dirty air filter image of a dirty air filter

Engine air, fuel, and cabin air filters are essential parts of your vehicle, yet they are often overlooked when it comes to regular maintenance. When these filters become clogged or worn, they stop performing correctly and can negatively affect your vehicle’s performance. 

But what do these filters do? How often should you replace them? And what signs indicate that it's time for a replacement? We’re here to answer all your pressing fuel and air filter questions, and we can provide expert replacement services if your filters are no longer up to par.

What Does an Engine Air Filter, Cabin Air Filter, or Fuel Filter Do?

Filters are designed to catch potentially harmful debris before they enter an area where they should not, including the combustion chamber, fuel injectors, your vehicle's cabin, and more. Once a filter is no longer working properly, it can lead to decreased performance of that system. And, if left untreated too long, it could damage components within that particular system.

What Does an Engine Air Filter Do in a Car?

The engine air filter helps to keep harmful contaminants from entering your engine, ensuring that only clean air, without debris, reaches this vital component. When this filter becomes clogged, you may experience a long number of issues with regard to your vehicle's engine.

What Does a Cabin Air Filter Do?

Cabin air filters help prevent dust, pollen, dirt, and other pollutants from entering the cabin through your A/C and heat vents. If you have allergies or a sensitive respiratory system, the cabin air filter is essential for creating a more comfortable driving environment.

What Does a Fuel Filter Do?

Fuel is generally "clean" when it leaves the refinery, but when it’s transferred to a truck or sits in a storage tank at a gas station, it can become contaminated with debris. This debris can be transferred into your fuel tank when you fill up your vehicle. The fuel filter helps to prevent these contaminants from clogging your fuel injectors, thus helping to maintain fuel economy and performance. If a fuel filter becomes clogged, it can cause fuel pressure to drop. You may also experience issues with starting your vehicle or have a hard time keeping it running.  

How Often Should an Engine Air, Fuel, or Cabin Air Filter Be Replaced?

If you’ve ever used a furnace or air conditioning system at home, you’ve likely replaced a filter at some point. The filters in your car are no exception. To keep them working their best, it’s generally recommended that you get your filters replaced every 12 months or 12,000 miles. 

Check your scheduled maintenance interval online or reference your owner’s manual for more details on how often to replace your filters, as well as timeframes for other recommended services. At Firestone Complete Auto Care, our expert technicians even check your cabin and engine air filters during a full-service oil change

What Happens to Engine Air, Fuel, and Cabin Air Filters as They Get Older?

Any filter — home, auto, or otherwise — will eventually age and become clogged with pollutants and debris. When that happens, it becomes harder for the air or fuel to continue traveling through the filter, which can cause issues. Eventually the filter media may break, allowing contaminants to reach parts the filter is meant to protect.

When your air filter is clogged and heavily restricts airflow, it may lead to incomplete combustion, and ultimately reduced engine power. In turn, a clogged cabin air filter can lead to under-performance of the A/C system, causing weak airflow from the cabin vents. It can also lead to unwanted, unfiltered air in the cabin.

As for a clogged fuel filter, that can cause a reduction in engine power, low fuel pressure to the injectors, poor acceleration, and lousy fuel economy — not to mention a potential breakdown. 

What is the Benefit of Replacing an Engine Air, Fuel, or Cabin Air Filter?

The purpose of each filter is clear: to trap and protect. Like a clogged drain, a dirty filter starves the system of vital air or fuel and makes each system it protects work harder to do its job. In short, regularly replacing your filters can positively impact the quality of your car’s performance.

  • Engine Air filter: Engine protection is the name of the game. So is engine performance. Acceleration can improve after replacing a clogged air filter.
  • Cabin air filter: Cabin air filters are engineered to trap things like pollen, dust, mold spores, smoke, soot, and smog — none of which belong in your nose.
  • Fuel filter: With a new fuel filter, you may notice a boost in fuel efficiency and overall performance. And with the cost of gas these days, those savings can add up.

Signs You Need a Replacement Engine Air, Fuel, or Cabin Air Filter

Once a filter is old and full of crud, you may notice a decline in the performance of that system. If you see a drop in fuel economy, a decrease in power and performance, or notice the A/C and heating systems not blowing air properly, it may be time to replace one or more filters. Spot the symptom. Replace the filter.

What Happens If You Don’t Change Your Engine Air Filter?

Clogged engine air filters can reduce engine power, decrease throttle response, weaken acceleration, and increase engine wear. And in very old engines, they can also cause poor gas mileage. If you’re worried about your filter, keep an eye out for:

You can also visually inspect your engine air filter. The filter box is typically located under your hood (check your owner’s manual for the exact location) and can usually be opened by releasing the latches or removing the screws. A clean filter is generally white, off-white, yellow, or red, and it may become darker as it collects more dirt. If you live in a dusty or sandy area, you may also need to replace your filter more often. 

Note: When inspecting your engine air filter, look for an accumulation of debris. This build-up can overwhelm the filter. In which case, to minimize any chance of debris falling in, avoid removing the filter from the housing.

When Should You Replace Your Cabin Air Filter?

Because the cabin air filter helps clean the air that enters your cabin, you’ll likely notice when something is off. Some signs your cabin air filter is due for replacement include:

  • Weak airflow from the vents when using heating or A/C
  • Strange odor coming from the vents
  • Reduced air quality in the cabin
  • Unusual noise or whistling sound when using vents
  • Heating or A/C system don't work as well as they used to

Like the engine air filter, you can visually inspect your cabin air filter to gauge how dirty it is. For vehicles that one, they are often located behind the glovebox. Check your owner’s manual for instructions on how to access the filter. 

What Are the Signs That Your Fuel Filter is Bad?

When your fuel filter is clogged, you’ll feel it in your car's performance. Delaying a replacement can lead to low fuel pressure that stops your engine in its tracks. It could be time to replace your fuel filter if you notice:

  • Sluggish engine performance (sputtering horsepower, dragging)
  • It takes longer to start your car, or your car won’t start at all
  • Engine stalling
  • Drop in MPG’s
  • Misfiring

While checking your fuel filter at home is possible for most external fuel filters, dealing with gasoline requires an abundance of caution. If you think something’s wrong with your fuel filter, we recommend bringing your vehicle in to be inspected by a professional.

Where Can I Get My Engine Air, Fuel, and Cabin Air Filters Replaced? 

If you’re reaching the maintenance interval on your filters, or they just aren’t performing as they should, consider getting a replacement. Firestone Complete Auto Care is a proud supplier of the latest and most effective filters, and we will help you find the right fit for your vehicle’s specifications. 

What Is Involved in an Engine Air, Fuel, or Cabin Air Filter Replacement?

Filter replacement is usually pretty simple. Most air filter replacements only require removing the old filter and installing the new one. In fact, some people decide to replace their air filters at home. However, more and more of today’s vehicle manufacturers are placing air filters in trickier, hard-to-access locations, largely for design and space efficiency purposes. 

To save yourself the time, energy, and frustration that comes with a hard-to-reach filter, bring your vehicle into your local Firestone Complete Auto Care. Our experts can efficiently handle the replacement and have you back on the road in no time.

How Long Does it Take To Replace the Filters on My Vehicle?

Times vary, but most filters can be replaced quickly, provided they’re in an easy-to-reach place. As for fuel filters, labor time may be more vehicle-specific. Hard-to-reach filters ultimately require extra service time. If this is the case, we’ll keep you informed on how long it will take. Hard or easy to access, we’ll replace your filter and have you on your way as soon as possible.

How Do I Get My Filters Replaced?

Filter out the bad stuff with Firestone Complete Auto Care. Schedule an appointment to get your filters replaced today.

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