In a 2011 Fiesta, there are two air filters you may encounter: the engine air filter, located in a rectangular airbox in the engine bay, and the cabin air filter, which, if your model is equipped with one, sits behind the glove box. The engine air filter sits in a plastic housing connected to the intake duct, while the cabin filter sits inside a dedicated housing behind the glove box. This article covers both locations and how to replace each filter.
Engine air filter: location and replacement
What follows explains where to find the engine air filter and the step-by-step process to replace it.
- Park on a level surface, turn off the engine, and open the hood.
- Locate the rectangular air filter housing in the engine bay, typically on the side toward the driver’s side with a large intake hose running to the throttle body.
- Release the locking clips or screws that secure the airbox lid. Some models use simple metal clips; others use screws or fasteners.
- Lift the lid, remove the old filter, and note its orientation (the filter has a specific direction of airflow indicated by arrows).
- Inspect the inside of the airbox for debris; wipe clean if needed, ensuring the seal around the box is intact.
- Insert the new filter in the same orientation as the old one, making sure it sits evenly and seals against the box.
- Close the airbox lid and resecure the clips or screws, then reconnect the intake hose to the throttle body.
- Close the hood and start the engine to verify normal operation and listen for any unseated components.
Keeping the engine air filter fresh helps optimize performance and fuel efficiency. Replace it according to Ford’s maintenance schedule or when you notice reduced acceleration, increased engine noise, or reduced fuel economy, especially in dusty conditions.
Cabin air filter: location and replacement
Not all 2011 Fiesta models include a cabin air filter. If your car has one, it is located behind the glove box and requires easing the glove box down to access the filter housing. The exact steps can vary by market and trim, so consult your owner’s manual if you’re unsure.
- With the glove box open, look for side stops or a damper on the right side and gently release or depress them to allow the box to drop down.
- Lower the glove box to reveal the cabin air filter housing behind it.
- Remove the housing cover or panel to access the filter.
- Take out the old filter and inspect the area for debris or leaves; wipe if necessary.
- Install the new filter with the airflow arrows pointing toward the blower motor, then reseat the housing cover.
- Raise the glove box back into place and ensure it latches securely.
After replacing the cabin filter (if equipped), turn on the HVAC system to verify air is flowing properly through the vents. If you notice strange odors or reduced airflow, recheck the filter orientation and reseat the housing.
Summary
For a 2011 Ford Fiesta, the engine air filter sits in the engine bay inside a rectangular airbox, accessible by unclipping the box lid. If your model has one, the cabin air filter sits behind the glove box and requires lowering the glove box to access the filter housing. Always confirm with your owner’s manual or a trusted mechanic for your specific market/trim, as configurations can vary. Regular inspection and timely replacement help maintain engine performance and cabin air quality.