The cabin air filter is the filter responsible for filtering the air that is fed into the vehicle’s heating and air conditioning systems. The filter traps dust, pollen, and other foreign particles, preventing them from entering the vehicle and polluting the cabin. Since they work in essentially the same fashion as a regular engine air filter, cabin air filters get dirty and should be replaced when they become excessively contaminated, or at the regular service interval recommended by the manufacturer. Usually a dirty cabin air filter will produce a few symptoms that can notify the driver that attention may be required.
Poor air flow
The most common symptom associated with a bad cabin air filter is poor air flow from the vehicle’s interior vents. An excessively contaminated cabin air filter will not be able to filter the incoming air as effectively as a clean filter would. As a result, this will cause restricted air flow for the AC system. Additionally, this will cause the vents to blow with noticeably less force, reducing the overall cooling capacity of the AC system, and will also place an additional strain on the AC blower motor.
Unusual odor from the vents
Another symptom of a bad or failing cabin air filter is an unusual odor coming from the vehicle’s interior vents. An excessively contaminated filter may produce a dusty, dirty, or musty smell. The smell may become more pronounced when the air is turned on, and may make the cabin uncomfortable for the passengers.
A cabin filter is a simple component that should be replaced when necessary to keep the AC system working as efficiently as possible, and to keep the cabin as comfortable as possible for the passengers. If you suspect that your cabin filter may be dirty, have the vehicle examined by a professional technician, such as one from YourMechanic, to determine if your car is due for a cabin air filter replacement.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Cabin Air Filter and was authored by Eduardo Ruelas.