Auxiliary Water Radiator, CSF - F22 M240i, F30 340i, F32 430i/440i, F87 M2 N55

Aux cooler upgrade for early B58 models and F87 M2 N55.

Thicker core = more surface area and capacity for improved cooling performance.

This CSF radiator replaces BMW part number 17118625447 (17 11 8 625 447) and is a auxiliary (secondary) coolant radiator upgrade for F22 M240i and F87 M2 (2016-2018). It also fits F30 340i and F32 430i/440i with the optional M Sport trim package AND M Sport brake option. This is the small radiator located in the wheel wells fed by the outer bumper ducts and provide additional coolant capacity and cooling surface area. Cars without M Sport do not have this radiator (but may have a different one, see below).

The thicker core increases capacity while the innovating CSF B-tube design and more cooling rows increases surface area. Both combine to reduce heat soak of your coolant and promote more stable coolant temps. This is a necessity for track or hard driving where temperature spikes will lead to reduced power or limp mode.

CSF aux radiator features -

• 42mm 2-row high-performance core
• 31% increase in core size over original
• CSF B-tube technology (more surface area)
• OEM plug-and-play* upgrade with original hoses
• OEM Style "Quick Connect" Inlet/Outlet connections
• 100% All-Aluminum TIG-Welded Construction
• Includes mounting frame (17218625445)
• Includes Detachable Rock Guard
• Satin Black Finish for OEM+ Look
• 2 Year Limited Warranty

Fitment Notes:
*340i/440i: Every 340i/440i has two aux radiators - one in each wheel well for both ends of the front bumper. BMW used multiple radiators depending on the options and intended use. This radiator is designed around the highest spec - M Sport trim package AND M Sport brake option. This is a fairly rare combination but the radiator can be made to fits cars with only one, or even none, of those options. Other models without an M Sport option likely have different aux radiators, BMW part numbers 17117628057 or 17117600697. See the options breakdown below. When using this on cars without M Sport, different mounting brackets and trimming of plastic ducts and shrouds is required.

My car has M Sport trim (0337) + M Sport brakes (02NH): this radiator is a drop-in replacement on both sides (order 2).
My car has M Sport brakes (02NH): this radiator is a drop-in replacement on both sides (order 2).
My car has M Sport trim (0337): this radiator will fit both sides with all new brackets and frame.
My car has Sport package (ZSP or P7ACA): this radiator will fit both sides with all new brackets and frame.
My car has the Base package (non-Sport, non-M Sport): this radiator will fit both sides with all new brackets and frame.

F22 M240i: Drop-in replacement for both left and right side radiators. No additional brackets or frames should be necessary.

F87 M2: for 2016-2018 N55 models only. Drop-in replacement for the left-side (driver) radiator in the wheel well. The right side cooler is for engine oil cooling (see CSF #8104 or BMW 17217618360).

Mounting Frame: the CSF aux radiator includes a mounting frame that is used in place of the original (BMW part #17218625445). There are other brackets and frames that may be required, depending on vehicle options. See Related Items below.

All CSF radiators receive design and development in the USA with additional wind tunnel, vibration, thermal cycle, burst pressure, and salt spray testing done at their production facilities in Southeast Asia. During manufacturing, radiators are individually tested for leaks and receive a 30-point inspection prior to shipping. This part is a much higher level of quality than typical Chinese factory parts. CSF is an OE supplier to several manufacturers as well as providing private-label products for other radiator brands. CSF radiators have a two year warranty.

For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.