The cabin air filter on the VW Jetta is designed to prevent pollution, pollen and other allergens from entering the cab of the vehicle during operation. The filter is placed in the air evaporative system in the engine compartment, where the air intake to the vehicle bolts to the firewall. Jetta owners with a high sensitivity to allergies will benefit from replacing the filters, which, similar to any other filters, can become clogged after time. In addition, on models equipped with A/C, replacement filters at scheduled maintenance intervals will provide better quality of air intake, as well as regular defrost and vent air intake.
Open the hood of the Jetta, with the engine turned off. Approach the passenger side cowl vent, located just below the windshield wiper arm.
Use the Phillips screwdriver to unscrew the four plastic trim screws retaining the cowl vent in place.
Pull the rubber cushion located at the bottom of the cowl vent from left to right, until the sectional piece is removed (halfway across the length of the engine compartment).
Remove the cowl vent to expose the filter frame.
Push down on the two retaining tabs of the filter and frame assembly, then pull slightly outward and then upward to remove the frame and filter assembly.
Unseat the old filter from the filter frame, taking note the directional flow of the filter (usually marked with an indicator arrow on the side of the frame).
Insert the replacement filter into the frame, making sure the four locking tabs at the top of the frame align properly with the ribs of the filter and the directional flow is correct.
Reinsert the frame and filter tray into the housing and then push slightly downward on it, until the two locking tabs of the frame click into place.
Replace the cowl vent and retaining screw tabs, then replace the rubber cushion.
