BMW X models utilize a HVAC fresh air cabin microfilter. The microfilter helps eliminate dirt and dust particles from entering the vehicle interior. It also protects HVAC system components from contamination. A dirty heater core would not provide sufficient heat and a dirty evaporator would not provide sufficient cooling. The microfilter is located in the wiper cowl area beneath a lid.
BMW recommends replacing the fresh air cabin microfilter every 15,000 miles or every other oil change.
Replace air filter once a year or more frequently if you drive in a dusty area. I suggest checking each time you change your engine oil, assuming you are changing your oil every 5,000 miles. It's easy to remove to inspect it and replacing it early will help you maintain your maximum fuel economy.
Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches.
Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability.
Our vehicle may vary slightly from yours as models do change and evolve as they grow older. If something seems different, let us know and share your info to help other users. Questions or want to add to the article? Leave a comment below. When leaving a comment, please include your vehicle information.
The cabin microfilter is located at the center of the wiper cowl, below a lid (red arrow).
Clean any debris (red arrow) from microfilter housing, this will prevent premature filter failure. The drains for the filter housing (inset) can also become plugged, causing leaks into the passenger footwell. Next, slide new microfilter into place, then install lid and fasteners. Be sure to properly align microfilter lid. If misaligned, water can leak into your vehicle.