In brief, the cabin air filter is located behind the glove box on the passenger side of the dashboard; you access it by lowering the glove box and removing a rectangular cover to replace the filter.
Location and access
To locate and access the filter, you’ll work from the passenger-side dashboard. The filter is not in the engine bay; it's in the HVAC housing inside the cabin.
- Open the glove box and remove its contents.
- Squeeze the sides of the glove box inward to release the stops and allow the box to drop down (some models use a damped hinge; releasing it may require a gentle push).
- Behind the glove box you’ll see a rectangular access panel/door covering the cabin air filter.
- Press the tabs or gently slide the panel to remove the cover and expose the filter.
- Carefully pull out the old filter and note the orientation of the arrows on the frame.
With the new filter ready, proceed to install it in the correct orientation and reassemble the panel and glove box.
How to replace the filter safely
Follow these steps to install a new cabin air filter and re-secure everything without leaving parts loose.
- Insert the new filter into the housing, making sure the arrows point in the direction of airflow (toward the interior/blower). The filter should sit flat and fully seated in the housing.
- Reattach the access panel/door until it is secure with the tabs or screws (if used).
- Raise the glove box back into its original position and ensure the stops/damper are engaged so the glove box opens and closes smoothly.
- Test the HVAC system by running the fan on a low setting to confirm there are no unusual noises and that air flows evenly from the vents.
It may be worth noting that some 2013 Optima trims may require slightly different steps or additional clips. If you encounter resistance, consult the owner’s manual or contact a Kia service professional for assistance.
Maintenance and tips
Replacement intervals and filter choices
Most owners replace cabin air filters every 12,000–15,000 miles or at least once a year, but dusty or heavily polluted environments may require more frequent changes. When choosing a replacement, consider filters with higher efficiency ratings (like higher MERV) that are compatible with your vehicle’s HVAC system. Check the filter size printed on the existing filter or in the owner’s manual to ensure the correct fit.
Always dispose of the old filter properly and handle new filters with clean hands to avoid introducing debris into the HVAC system.
Summary
The cabin air filter on a 2013 Kia Optima is located behind the passenger-side glove box. Access it by lowering the glove box to reveal the rectangular filter housing, replace the filter with proper orientation, and reassemble. Regular replacement helps maintain clean cabin air and HVAC performance.