How to Change an Engine Air Filter (10-Minute Job)

• The correct filter for your year, make, model and engine size.
• A flat screwdriver or a 10 mm socket, depending on how the airbox is fastened.
• A shop towel or vacuum for the housing.

• 1. With the engine off and cool, find the airbox — a black plastic box connected to the intake tube.
• 2. Release the clips or undo the screws around the lid. Lift the lid without straining the intake tube or any attached sensor wiring.
• 3. Lift the old filter straight out and note which way up it sits. Take a photo if it is not obvious.
• 4. Wipe out loose debris from the lower housing. Do not blow compressed air toward the intake.
• 5. Seat the new filter with the rubber sealing edge against the housing lip, all the way round.
• 6. Refit the lid, tighten evenly, and make sure every clip is latched. An unsealed airbox lets unfiltered air in — worse than a dirty filter.

Every 15,000 to 30,000 miles for most drivers. Dusty roads, construction routes and long unpaved commutes push that down to 10,000–12,000 miles.

Inspect rather than guess: hold the filter up to a light. If light passes through most of the pleats, it is fine. Grey is normal; blocked pleats, oil saturation or visible debris packed into the folds mean replace.

The cabin air filter cleans the air entering the interior, usually behind the glovebox. It is a separate job on a separate interval, typically 15,000–25,000 miles or annually if you suffer from allergies. Musty vents and weak airflow point at that filter, not the engine one.

On a modern fuel-injected engine, barely. The ECU compensates for restricted airflow, so a mildly dirty filter costs almost nothing in fuel. A severely blocked filter does reduce power and can trigger fuelling faults. Change it for engine protection and throttle response, not for a mileage number.