Is Your Subaru Cabin Air Filter Malfunctioning?

Subaru vehicles are known for their durability, reliability, and efficient performance. However, like any other car, Subarus need regular maintenance to keep them running smoothly. One crucial part of maintaining your Subaru’s performance is ensuring that its cabin air filter is in good condition. The cabin air filter is responsible for keeping the air inside your car’s cabin clean and free from pollutants, dust, and debris.

Over time, the cabin air filter can become clogged and dirty, leading to a reduction in air quality inside the car. In this article, we will discuss how to identify a malfunctioning Subaru cabin air filter and the consequences of not replacing it on time.

What is a Cabin Air Filter?

Before diving into the signs of a malfunctioning cabin air filter, it is important to understand what a cabin air filter is and what it does. The cabin air filter is a part of the ventilation system in your car that filters out dust, pollen, pollutants, and other airborne particles from entering the cabin. It is typically located behind the glove box or in the dashboard, depending on the make and model of your Subaru.

Signs of a Malfunctioning Cabin Air Filter:

Reduced Airflow

One of the most noticeable signs of a malfunctioning cabin air filter is a reduction in airflow. As the filter becomes clogged with dirt and debris, the air that comes through the vents becomes restricted, leading to reduced airflow. This can make it harder to regulate the temperature inside your car, leading to discomfort for you and your passengers.

Unpleasant Odors

If you start to notice unpleasant odors coming from your car’s air vents, it may be a sign that your cabin air filter is malfunctioning. A dirty or clogged filter can cause mold and mildew to grow inside the ventilation system, leading to foul smells emanating from the vents.

Increased Allergies or Respiratory Issues

A cabin air filter that is not functioning properly can also have an impact on your health. If you or your passengers start to experience increased allergies or respiratory issues, it could be a sign that your cabin air filter is not doing its job of filtering out pollutants and other allergens.

Noisy HVAC System

If your HVAC system starts to make more noise than usual, it may be a sign that your cabin air filter is clogged. As the filter becomes dirtier, it can restrict airflow, causing the blower motor to work harder to push air through the system. This can lead to increased noise coming from the HVAC system.

Consequences of Not Replacing a Malfunctioning Cabin Air Filter

Ignoring a malfunctioning cabin air filter can have serious consequences for your car’s performance and your health. If the filter is clogged, it can restrict airflow, making it harder to regulate the temperature inside your car. This can cause your HVAC system to work harder, leading to increased wear and tear on the system and potentially costly repairs.

In addition, a dirty or clogged cabin air filter can have an impact on your health. It can cause respiratory issues, allergies, and other health problems if you continue to breathe in polluted air inside your car.


Regularly checking and replacing your Subaru’s cabin air filter is essential for maintaining the performance of your car and ensuring the health and safety of you and your passengers. If you notice any of the signs of a malfunctioning cabin air filter, such as reduced airflow, unpleasant odors, increased allergies, or noisy HVAC system, it is important to have it checked by a professional mechanic and replaced if necessary. By doing so, you can ensure that your car’s ventilation system is functioning properly and that you are breathing clean