The Sentra uses two filters: an engine air filter and a cabin air filter.
In more detail, the engine air filter cleans air entering the engine, while the cabin air filter cleans air circulating inside the vehicle’s cabin. Replacing both at recommended intervals helps maintain engine performance, fuel efficiency, and interior air quality.
Engine air filter
Before replacing the engine air filter, it helps to know where it sits and what you’ll need. The engine air filter sits in the air intake box in the engine bay, and you’ll typically replace it with a standard disposable paper element or an equivalent aftermarket filter.
Here are the typical steps to replace the engine air filter on a 2018 Sentra:
- Open the hood and locate the air intake box, usually on the side of the engine bay.
- Unclip or unscrew the lid to access the filter housing.
- Remove the old filter and inspect the interior of the housing for debris.
- Wipe the inside of the box with a clean, dry cloth if needed.
- Insert the new filter with the airflow arrow pointing toward the engine.
- Re-seat the lid and secure the clips or screws.
- Close the hood and start the engine to ensure proper operation and no air leaks.
Regular engine air filter replacement helps sustain engine performance and fuel economy, and reduces the risk of unmetered air entering the intake system.
Cabin air filter
Access to the cabin air filter is usually behind the glove box or a small panel beneath the dashboard. The cabin filter is a rectangular panel that traps dust, pollen, and other particulates to improve interior air quality.
Here are the typical steps to replace the cabin air filter on a 2018 Sentra:
- Open the glove box and locate the cabin filter housing behind or near it.
- Remove the cover or panel to expose the filter.
- Take out the old filter and inspect the surrounding area for debris.
- Clean the housing area if needed, then insert the new filter with the correct orientation (airflow direction is usually marked).
- Reattach the filter cover and close the glove box or panel.
- Run the HVAC system briefly to confirm air flow feels normal and there are no unusual smells or noises.
Replacing the cabin filter improves interior air quality and HVAC performance, especially in dusty or polluted environments.
Summary
For a 2018 Nissan Sentra, you’ll be dealing with two filters: the engine air filter and the cabin air filter. The engine filter sits in the engine’s air intake box in the engine bay, while the cabin filter lives behind the glove box and filters air entering the cabin. Replacement intervals vary by driving conditions, but many owners replace both filters during scheduled maintenance or when you notice reduced engine performance or a decline in interior air quality. Always consult the owner’s manual or a trusted parts supplier for exact part compatibility and installation tips, and consider OEM or quality aftermarket replacements for best results.