The engine air filter is located in the engine bay’s rectangular air box on the driver’s side front, and the cabin air filter sits behind the glove box on the passenger side. These two filters protect the engine and interior air quality, so knowing their locations helps with routine maintenance.
These filters keep dust, pollen, and debris from entering the engine and the cabin. Replacing them at the intervals recommended by GM helps maintain performance, fuel efficiency, and interior air quality. Always consult your owner’s manual for the exact replacement intervals and filter part numbers for your specific Sierra configuration.
Engine air filter location and replacement
Steps to access and replace
Follow these steps to locate and replace the engine air filter in a 2020 GMC Sierra.
- Park on a level surface, turn off the engine, and open the hood. Locate the large rectangular black plastic air box on the driver’s side front of the engine bay.
- Release the clips or screws securing the lid of the air box and lift the lid off. Some models use metal clips; others use quick-release clamps.
- Carefully lift out the old engine air filter element and note its orientation (the filter typically has an arrow indicating the direction of airflow toward the engine).
- Wipe any dust from inside the air box with a clean rag if needed. Do not use water or cleaners inside the box.
- Insert the new filter with the same orientation as the old one, ensuring it sits snugly in the box and the seal is even around the edge.
- Replace the lid and secure the clips or screws. Make sure the lid is firmly seated to prevent unfiltered air from entering.
- Close the hood and start the engine to confirm everything sounds normal.
Replacing the engine air filter is a quick maintenance item that can improve throttle response and overall engine efficiency when the filter is dirty or clogged.
Cabin air filter location and replacement
Steps to access and replace
Follow these steps to locate and replace the cabin air filter behind the glove box in a 2020 GMC Sierra.
- Park on a level surface, turn off the ignition, and locate the glove box on the passenger side. Remove items from the glove box and prepare to access the filter housing behind it.
- Gently release the glove box by squeezing the sides or removing the dampener arm if your model uses one, allowing the box to drop down enough to access the filter housing.
- Locate the cabin air filter cover (a rectangular panel) and release its tabs or screws to remove the cover.
- Remove the old cabin air filter, noting the correct orientation (usually with an arrow pointing toward the rear of the vehicle).
- Wipe the inside of the housing with a clean cloth to remove any debris.
- Insert the new cabin air filter with the correct orientation, ensuring it sits flat and fully covers the intake opening.
- Reinstall the filter cover and secure it, then close the glove box and return any removed items.
A fresh cabin filter helps maintain interior air quality and can improve HVAC performance, especially in dusty or polluted environments.
Summary
The 2020 GMC Sierra has two distinct air filters to consider: the engine air filter sits in the engine bay’s air box on the driver’s side front, and the cabin air filter sits behind the glove box on the passenger side. Replacing both filters follows straightforward steps: unclip or unbolt the air box to swap the engine filter, and lower the glove box to access and replace the cabin filter. Always use the correct part numbers for your specific model and refer to the owner’s manual for recommended replacement intervals and any model-specific quirks. Regular replacement supports engine efficiency and better interior air quality.