The cabin air filter is probably the most forgotten filter in your car when it comes to car service, and many people do not know much about it.

An old clogged cabin air filter vs. a new one can make a huge difference when it comes to the comfort of your ride, and you may not even notice it.

Fortunately, we will teach you everything you have to know about the cabin air filter in this guide.

We will talk about the function, location, replacement cost, and how you can determine if it is time to replace it.

What is a Cabin Air Filter?

Cabin Air Filter Engine

The cabin air filter removes harmful pollutants like pollen and dust from the outside air, which you are breathing within the car. It also prevents leaves and other dust from getting stuck in the blower motor.

Your car takes in air from outside and blows it into the cabin directly towards you. As you may understand, there are many dangerous particles and dust on the roads, which is why we need a filter to remove these particles and dust from the road.

It also prevents leaves and other dust from getting into the system to get stuck in the blower motor. This could create a horrible noise inside your car – which you probably already noticed if you owned an older car without a cabin air filter before.

So now, when you know what a cabin air filter is, let’s find out what will happen if you do not replace the filter in time.

Symptoms of a bad cabin air filter

  1. Bad Smell
  2. Low air flow through vents
  3. Foggy or icy windows
  4. Allergy symptoms
  5. Light whistling noise from the air vents

These are the symptoms you may notice if you have a bad or an old cabin air filter. Here is a more detailed list of the most common symptoms of a bad cabin air filter:

Bad Smell

Bad Car Smell E1609777166642

The first thing you will notice if you have a bad or old cabin air filter is getting a horrible smell inside the car. When the car is filtering the air from the outside, it will collect all dust that will get stuck in the filter, creating a bad smell after a while.

It will also filter condense through the filter during this filtering process, which will get stuck there. As you might understand, this will cause mold in the filter after a long time of use, and therefore you need to replace the filter within the specified schedules to prevent it.

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Low air flow through vents

Air Vents Car

The next thing that you may notice is that the airflow’s efficiency through the vents has dropped recently. This happens because the cabin air filter filters all air that is going into the car.

If the filter has been used for a long time, the filter will get clogged, and less air will pass through it. This will cause the airflow to drop drastically, and it can even cause it to stop blowing anything at all!

Foggy or icy windows

Foggy Icy Windows

As I told you before, water condense will get stuck in the cabin air filter, which will cause mold inside of the filter. This can cause the filter to collect condense more often, and this water condense will get blowed into the car cabin.

This will cause the humidity level to increase a lot in the cabin, which will cause foggy windows or even icy windows on the inside if you live in a cold country. If you notice a lot more foggy or icy windows recently than before, it is definitely time to check the cabin air filter.

Allergy symptoms

Car Allergy

If you are sensitive to different particles and may even have an allergy to these things, you will notice that your allergy is getting worse while driving if you have a bad or old cabin air filter.

As we talked about before, all particles and dust from the outside air will get filtered and stuck in the cabin air filter. Even if they are on the other side of the filter, they can get into the car and cause allergy symptoms.

Light whistling noise from the air vents

Car Ac Not Blowing Cold Air

If the airflow is heavily restricted because of a clogged or bad cabin air filter, it can also cause it to make strange noises when the air is trying to pass through the filter.

If you hear a whistling noise from the air vents that weren’t there before – it is definitely time to inspect the cabin air filter and replace it if it’s bad.

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How often should you replace the cabin air filter?

Cabin Air Filter

Activated charcoal cabin air filters should be replaced once a year or every 15.000 miles (24000 km). Standard particulate cabin air filters should be replaced every other year or every 30.000 miles (48000 km).

To know when exactly to replace the cabin filter for your specific car model, you must consult the manufacturer’s repair manual or call your dealer to get the correct information for your vehicle.

The frequency of replacement does also depend on where you live. If you live in a dusty climate you will have to replace it much more often than if you live in a climate with clear air.

Air cabin filters are often quite cheap, and I recommend replacing the cabin air filter on most car models and filter types every year or every other year when you change the engine oil.

What happens if I do not replace the cabin air filter?

Dirty Cabin Air Filter

If you do not replace the cabin filter, you will notice symptoms like a bad smell, low airflow through the vents, foggy or icy windows on the inside, allergies, or whistling noises from the air vents.

Bad smell in your car can easily get stuck in the interior and the value of your car may decrease and it may even damage parts inside the air conditioner. Therefore it is always recommended to keep your cabin air filter up to date.

Where is the cabin air filter located?

The cabin air filter is in most cars located behind the glove box or behind a cover under the front windshield from the engine bay. If you know where the blower motor is located, look close to it!

In many car models, you will need to remove the glove box to access the filter. Many cabin air filter manufacturers will give you instructions on how to replace the cabin air filter for your specific car model on a paper following with the filter.

Generally, in many Asian cars, the filter is installed behind the glove compartment, and in some cases, the glove compartment must be removed to replace the cabin filter.

It is often located behind a cover under the front windshield from the engine bay in European cars.

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Cabin Air Filter Replacement Cost

A cabin air filter costs 20$ to 50$ depending if you choose to buy a charcoal filter or a standard one. You can expect a total cost of 30$ to 90$ for a cabin air filter replacement cost.

The labor cost of replacing the cabin air filter is often quite low; in most cases, the replacement is done in a maximum of 30 minutes.

The cabin air filter price can differ a bit depending on if you choose to buy a charcoal cabin filter or a standard one. Charcoal filters are filtering the air better and are better suited for people with allergies.