In order to run, the engine needs a precise mixture of fuel and air. When outside air is drawn into the engine, the air filter prevents harmful dirt and debris from entering the system.
How does the air filter work?
Typically made of paper or foam suspended in a plastic frame, the air filter media catches the dirt and debris that comes in through the air intake.
What are the symptoms related to a bad air filter?
The filter will become dirty, but drivability problems are not typically noticed except in the extreme. Decreased fuel efficiency, stumbling, or rough running may be noted with a severely clogged air filter.
Can I drive with an air filter problem?
Because the filter clogs over time, the effects of a dirty filter will not be noticeable except with severe service conditions, such as consistent driving in a dusty or off-road area.
How often do air filters need to be replaced?
Replacement frequency of the air filter will vary by vehicle and driving conditions. We typically see the engine air filter replaced at approximately 40,000 miles
How are air filter issues diagnosed?
A visual inspection of the filter will be sufficient. The technician will open the air filter box and remove the filter. The airbox will be inspected for road debris, and the filter will be assessed for cleanliness.
How is an air filter replaced?
The procedure is the same as the inspection. The technician will open the air filter box and remove the filter. Typically the filter is a cartridge that can simply be swapped for a new one. Some high end cars may have two filters in two air boxes that need to be changed at the same time.
We recommend replacement of the air filter every year or 12,000 to 15,000 miles.
Air filters will need to be replaced more often in vehicles driven in dusty and sandy areas.
RepairPal Recommendations for air filter issues
Most engine air filters are very low cost, when going through the trouble to inspect them, they should be replaced unless they have been recently serviced.
BMW 335d Air Filter Replacement Cost by Year
The average cost for a BMW 335d Air Filter Replacement is between $149 and $177 but can vary from car to car.
