The 2018 Honda Civic has two air filters: the engine air filter in the engine bay and the cabin air filter behind the glove box. This article explains exactly where they are and how to replace them.
Engine air filter: location and replacement
The engine air filter sits in a rectangular plastic housing in the engine bay on the passenger side, toward the front of the car. It’s part of the air intake that channels outside air into the engine. Replacing it helps maintain performance and fuel efficiency, especially in dusty conditions.
Follow these steps to locate and replace the engine air filter:
- Park on a flat surface, engine off, and cool. Open the hood and locate the engine air box on the passenger side near the front of the engine bay.
- Release the clips or screws that hold the air box lid in place. Some models use simple metal clips; others may have a few screws to loosen.
- Lift or tilt the lid to access the filter. Remove the old filter, noting its orientation relative to the air flow.
- Clean the inside of the air box with a dry rag to remove loose debris. Ensure there are no foreign objects inside.
- Insert the new engine air filter with the airflow arrows pointing toward the engine, then reseal the lid and secure the clips/screws.
- Close the hood and start the engine to confirm it runs smoothly.
Regular replacement of the engine air filter, typically every 30,000 to 40,000 miles under normal conditions, keeps the intake system clean. If you drive in heavy dust or off-road conditions, replace more frequently.
Cabin air filter: location and replacement
The cabin air filter is located behind the glove box on the passenger side. It cleans the air that enters the cabin through the HVAC system. Accessing it requires lowering the glove box and removing a small cover or panel to reach the filter.
Follow these steps to locate and replace the cabin air filter:
- Park on a level surface, turn the ignition off, and open the glove box. If the glove box has stoppers, gently press in or remove the stoppers to allow the box to drop down.
- Look for a rectangular access panel or door on the far side of the glove box area and pull it open to reveal the cabin air filter housing.
- Release the retaining clips or screws holding the filter cover. Remove the old cabin air filter, noting the correct orientation for the new one (usually with arrows pointing in the direction of airflow).
- Wipe away any dust from the housing, then insert the new filter and reseal the cover.
- Reassemble the glove box and ensure it closes securely. Start the car and run the HVAC to confirm proper airflow.
Cabin air filter replacement is typically recommended every 15,000 to 30,000 miles, depending on driving conditions and the environment. If you notice reduced airflow or a musty odor, it’s a good time to replace it.
Notes and tips
Tools are usually not required for the engine air filter, but a flat-head screwdriver may help with stubborn clips. Always verify the correct orientation of filters by following the printing on the filter itself, which includes an airflow arrow. If you’re unsure or uncomfortable performing the replacement, a mechanic or quick-service center can do it quickly.
Summary
The 2018 Honda Civic houses two filters: the engine air filter in the engine bay on the passenger side and the cabin air filter behind the glove box on the passenger side. Both are user-serviceable with basic steps and common tools, and following recommended replacement intervals helps maintain engine performance and interior air quality.