aFe POWER Cold Air Intake System Installation Manual
Brand: aFe POWER
Product: Magnum FORCE Stage-2 Cold Air Intake System
Part Numbers: 52-31912, 51-31912, 54-31912
Compatible Vehicles:
- BMW 335i/xi (E9X) | Years: 2011-2013 | Engine: L6-3.0L (t) N55
- BMW 135i (E82/E88) | Years: 2011-2013 | Engine: L6-3.0L (t) N55
- BMW X1 35ix (E84) | Years: 2011-2015 | Engine: L6-3.0L (t) N55
This manual provides instructions for installing the aFe POWER Magnum FORCE Stage-2 Cold Air Intake System.
Important Information & Safety Precautions
- ⚠️ Please read the entire instruction manual before proceeding.
- Ensure all components listed are present.
- If you are missing any of the components, call customer support at 951-493-7100.
- Ensure you have all necessary tools before proceeding.
- Do not attempt to work on your vehicle when the engine is hot.
- Disconnect the negative battery terminal before proceeding.
- Retain factory parts for future use.
Parts Included
| Label | Qty. | Description | Part Number |
|---|---|---|---|
| A1 | 1 | Air Filter (Pro DRY S) | 21-90083 |
| A2 | 1 | Air Filter (Pro 5R) | 24-90083 |
| B | 1 | Tube | 05-31912B1 |
| C | 2 | Screws, M4 | 03-50490 |
Installation Instructions
Tools Required:
- 6mm nut driver
- 8mm nut driver
- T25 torq bit and driver
Removal of Original Equipment (OE) Components:
Refer to Figure A for steps 1-5
Figure A Description: An image showing a BMW engine bay with callouts pointing to the factory air-box and the Mass Air Flow (MAF) sensor area.
- 1. Unclip the factory air-box in four (4) places. [clip-location-1]
- 2. Loosen the first hose clamp after the Mass Air Flow (MAF) sensor. [hose-clamp-2]
- 3. Lift the OE tube up enough to disconnect the MAF sensor.
- 4. Remove the OE intake tube and air filter.
- 5. The lower half of the factory air-box should remain in place and will be reused.
Refer to Figure B for step 6-7
Figure B Description: A close-up view of a hand interacting with the clips on the factory air-box. An arrow indicates to "Press Inward" [press-inward], and another arrow indicates to "Press Down" [press-down].
- 6. If the Magnum FORCE Stage-2 Intake System Cover is used, the four (4) metal clips can remain in place.
- 7. If the intake is installed without the intake cover, the four (4) metal clips can be removed by pushing them all the way closed and then pushing down firmly.
Refer to Figure C for steps 8-9
Figure C Description: A close-up of the Mass Air Flow (MAF) sensor mounted on the original intake tube. The sensor has a "Continental" label and is secured by two screws.
- 8. Use a T25 Torx driver to remove the two screws securing the MAF sensor to the OE intake tube.
- 9. Pull the MAF sensor straight out to remove it from the OE tube.
Installation of aFe POWER Components:
Refer to Figure D for step 10
Figure D Description: An image showing the MAF sensor being installed into the new aFe intake tube using the provided M4 screws.
- 10. Install the MAF sensor into the new aFe intake tube using the supplied M4 screws.
Refer to Figure E for steps 11-14
Figure E Description: An image of the fully installed aFe POWER cold air intake system in the BMW engine bay, featuring the intake tube and a blue air filter.
- 11. Install either the PDS (Pro DRY S - Maximum convenience) or P5R (Pro 5R - Maximum Performance) aFe air filter onto the end of the tube. Ensure the intake can be installed as one assembly.
- 12. Plug the MAF sensor in first, then place the end of the tube into the OE coupling.
- 13. Press the aFe intake tube into place over the edge of the OE air box and tighten all clamps securely.
- 14. Black foam tape can be used to protect the surface of the air box or to tighten the fitment of the aFe intake tube to the OE air box.
Legal Notice
Legal in California for use on race vehicles only. The use of this device on vehicles used on public streets or highways is strictly prohibited in California and other states that have adopted California emission regulations.
For warranty information, visit: https://afepower.com/contact#warranty
