Symptoms
- Reduced airflow from vents even at high fan speed
- Musty or dusty smell when the fan or AC first turns on
- Windows take longer to defog than they used to
- Fan seems to work harder (louder) to produce the same airflow
Likely causes
- CommonFilter overdue for replacementCabin filters typically need replacement every 12,000–15,000 miles or annually, and get progressively clogged with dust, pollen, and debris.
- CommonDriving in dusty, pollen-heavy, or polluted conditionsFilters clog faster in construction zones, farmland, or high-pollen seasons.
- PossibleDebris or leaves entering the filter housingLarger debris getting past the intake screen can partially block the filter surface.
What to do
- Find your cabin air filter's location (commonly behind the glovebox, or occasionally under the hood or under the dash) using your owner's manual.
- Remove the filter and hold it up to a light; if little to no light passes through, it's clogged and due for replacement.
- Check the filter's replacement interval in your maintenance schedule and compare to your mileage/last replacement.
- Install a new filter facing the correct airflow direction, usually marked with an arrow on the filter frame.
- Reset any maintenance reminder if your vehicle tracks it, and note the date/mileage for next time.
Tools and parts
- Screwdriver (some glovebox designs)
Cabin air filter for your make/model/yearSearch: “cabin air filter”
When to call a pro
This is a simple DIY job; a mechanic or quick-lube shop can do it in minutes if you'd rather not access the glovebox area yourself.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.