Subaru Cabin Air Filter Replacement: A Complete DIY Guide
Replacing the cabin air filter in your Subaru is a simple, quick, and inexpensive maintenance task that anyone can do in about 10 minutes with no special tools required. Performing this replacement yourself can save you money compared to a dealership service and significantly improve the air quality inside your vehicle. This comprehensive guide provides detailed, model-specific instructions for every modern Subaru, from the Outback and Forester to the Crosstrek, Impreza, Ascent, and BRZ.
A clean cabin air filter is critical for the performance of your vehicle's heating, ventilation, and air conditioning (HVAC) system. This filter is responsible for cleaning the air that enters the passenger compartment through the HVAC system. It traps a wide array of contaminants, including dust, pollen, smog, mold spores, and other airborne particles. Over time, typically every 12,000 to 15,000 miles or once a year, the filter becomes clogged with this debris. A dirty filter restricts airflow, forcing the blower motor to work harder, which can reduce the efficiency of your air conditioning and heating. More importantly, a clogged filter can no longer effectively remove pollutants from the air you breathe, leading to unpleasant odors and potential allergy issues for you and your passengers.
Why You Should Replace Your Subaru's Cabin Air Filter
The primary reason for a timely replacement is the health and comfort of everyone in the car. For individuals with allergies or asthma, a clean cabin air filter is essential, as it removes allergenic pollen and spores from the incoming air. Furthermore, in areas with frequent wildfire smoke or high pollution levels, a fresh, high-quality filter acts as a first line of defense for your lungs. From a vehicle performance standpoint, a clean filter ensures maximum airflow. This means your defroster will work more effectively to clear foggy windows, and your air conditioner will blow colder air with less effort and noise. Ignoring this simple service can lead to a musty smell emanating from the vents, reduced HVAC performance, and, in rare cases, strain on the blower motor resistor or motor itself. The cost of a high-quality aftermarket filter is low, often between 40, while the dealership may charge over $100 for the same service. The financial savings and personal health benefits make this a highly worthwhile DIY project.
Locating the Cabin Air Filter in Your Subaru
In nearly all modern Subaru models (post-2010), the cabin air filter is located behind the glove compartment. This centralized location makes the process very similar across the lineup. You do not need to access the engine bay. The filter is housed in a dedicated slot that is easily reachable once the glove box is removed. Some older models may have a different setup, but for the vast majority of Subaru owners, the steps will involve working with the glove box area.
Tools and Parts You Will Need
The beauty of this job is its simplicity. You will only need a few basic items:
- A New Cabin Air Filter: Ensure you purchase the correct filter for your specific Subaru model and year. Popular brands include FRAM, Bosch, EPAuto, and Subaru Genuine Parts.
- A Flashlight: This will help you see into the filter housing.
- A Vacuum Cleaner (Optional but Recommended): Useful for cleaning out any leaves or debris that may have accumulated in the filter housing.
You will not need any screwdrivers, wrenches, or other tools for most models, as the glove box is typically held in place by dampers and stoppers designed for easy removal.
Step-by-Step Replacement Instructions
The following steps are universal for most Subaru vehicles like the Outback, Forester, Crosstrek, Impreza, and Ascent. The process for the BRZ is slightly different and will be covered in a separate section.
Step 1: Prepare Your Vehicle
Park your Subaru on a level surface and ensure the ignition is turned off. Apply the parking brake for safety.
Step 2: Empty the Glove Compartment
Remove all items from your glove box to make it light and easy to handle.
Step 3: Open and Remove the Glove Box
Open the glove box door. Look at the sides of the glove box compartment. You will see a damper arm on the right side that controls the slow-down motion of the glove box. Gently unclip this arm by pinching the ends and pulling it free. Next, on each side of the glove box, near the top, you will see a stopper or tab. Squeeze the sides of the glove box inward slightly. This action will allow the stoppers to clear the dashboard frame. Once both sides are clear, you can lower the glove box downward and carefully set it aside. It will remain attached by the light wire, so do not pull it away forcefully.
Step 4: Locate the Filter Housing
With the glove box removed, you will see a rectangular, black plastic cover. This is the cabin air filter housing. The cover is usually secured with clips or tabs.
Step 5: Remove the Old Filter
Press the tabs on the sides of the filter housing cover and remove the cover. You will now see the old cabin air filter. Take a moment to shine your flashlight into the cavity. You may see leaves or other debris. Use your vacuum cleaner with a hose attachment to clean this area thoroughly. Pull the old filter straight out. Take note of the airflow arrows printed on the frame of the old filter. These indicate the direction air should flow through the filter, which is always downward (toward the floor of the vehicle) in Subarus.
Step 6: Install the New Filter
Take your new filter and ensure the airflow arrows are pointing in the correct direction—downward. Slide the new filter into the housing, making sure it sits flat and secure. Do not force it. It should slide in smoothly.
Step 7: Reinstall the Filter Cover and Glove Box
Place the plastic cover back onto the filter housing and snap the clips securely into place. Now, lift the glove box back into position. Squeeze the sides to maneuver the stoppers back into their slots on the dashboard frame. Finally, reattach the damper arm on the right side. Close the glove box door. The operation should be smooth.
Step 8: Test the System
Start your Subaru and turn the HVAC fan to its highest speed. You should feel strong, unobstructed airflow from the vents. There should be no unusual noises from the blower motor. If the airflow seems weak or noisy, turn off the system and double-check that the filter is seated correctly and the housing cover is fully secured.
Model-Specific Considerations and Variations
While the process is largely identical, there are minor differences to be aware of depending on your specific model.
- Subaru Outback and Legacy: The process is exactly as described above. These models have a very straightforward glove box removal.
- Subaru Forester: The Forester follows the standard procedure. Some model years might have a small plastic pin on the left side of the glove box that needs to be removed by hand, but the squeeze-to-release method is most common.
- Subaru Crosstrek and Impreza: These models are identical to the Outback and Forester in terms of cabin air filter replacement. The glove box removal is precisely the same.
- Subaru Ascent: The three-row Ascent also uses the same glove-box-behind method. Due to its larger size, the glove box might be a bit bigger, but the removal steps are unchanged.
- Subaru BRZ: The BRZ (and its Toyota 86/Scion FR-S twins) is the notable exception. The cabin air filter is located under the dashboard on the driver's side. To access it, you must remove a plastic cover panel that is secured by clips or screws. This requires a trim removal tool or a screwdriver and is a slightly more involved process than the glove box method.
Choosing the Right Replacement Filter
When selecting a new filter, you have several options, each with its own benefits:
- Standard Particulate Filter: This is the basic replacement. It effectively captures dust, pollen, and other common particles.
- Activated Carbon Filter: This is a highly recommended upgrade. In addition to capturing particles, the activated carbon layer absorbs odors and helps reduce harmful gaseous pollutants from exhaust fumes. This is the best choice for most drivers, especially those in urban or high-traffic areas.
- HEPA Filter: Some aftermarket companies offer HEPA-grade filters that provide the highest level of particulate filtration. Ensure the filter is designed for your specific vehicle, as a filter that is too dense can restrict airflow.
Always check your owner's manual or use a retailer's fitment guide to guarantee you are buying the correct part number for your model year.
Conclusion
Replacing the cabin air filter in your Subaru is one of the easiest and most rewarding do-it-yourself maintenance tasks you can perform. It requires no mechanical skill, takes less than a quarter of an hour, and has an immediate positive impact on your driving environment. By following this detailed guide, you can ensure the air inside your vehicle remains clean and fresh, protect the components of your HVAC system, and save a significant amount of money on routine dealership servicing. Make it a habit to inspect your cabin air filter every oil change and replace it at least once a year for optimal performance and comfort.