CSF BMW G2X M340i/M440i/M240i High Performance Engine Oil Cooler

Drop-In High-Performance Engine Oil Cooler Built for BMW G2X M340i, M440i, and G42 M240i B58 Engines

The CSF 8372 High-Performance Engine Oil Cooler is a direct drop-in replacement for the 2019 and newer BMW G2X M340i, M440i, and G42 M240i equipped with the B58 engine and the factory oil cooler (requires BMW Motorsport Engineering Package). The 8372 utilizes CSF's Super-High Pressure 32mm 10-channel microtube core, which is 14 percent larger than the OEM 28mm core and delivers superior oil flow and maximum surface area contact for improved thermal management at stock and elevated power levels. The unit installs in the OEM location using the factory mounting hardware and coolant connections with no modifications required. This oil cooler is a direct OEM cross-reference to BMW part number 17218666121.

Key Features

• Super-High Pressure 32mm 10-channel microtube core is 14 percent larger than the OEM 28mm core
• Optimal oil flow geometry and maximum surface area contact for improved thermal management
• Drop-in fit installation in the OEM engine oil cooler location with no modifications required
• Compatible with factory BMW coolant connections and mounting hardware
• Direct OEM cross-reference: BMW part number 17218666121 (17 21 8 666 121)
• Designed for BMW G20 M340i, G22 M440i, and G42 M240i with B58 engine and factory oil cooler
• Supports stock and lightly modified B58 builds seeking better sustained oil temperature management

This Part Fits

Specifications

What Is Included

• 1x CSF 8372 High-Performance Engine Oil Cooler for BMW G2X M340i/M440i and G42 M240i

Frequently Asked Questions

This unit is a replacement for the factory BMW oil cooler that is included as part of the Motorsport Engineering Package (MEP) option. This means your vehicle must have been originally ordered with the MEP to have the factory cooler mounting location and coolant circuit present. It is a direct replacement for that factory unit, not a retrofit for vehicles without the MEP.

The 8372 is a direct cross-reference for BMW part number 17218666121. You can use this BMW OEM part number to confirm whether your specific M340i, M440i, or M240i has the factory oil cooler installed before ordering.

CSF's Super-High Pressure 32mm 10-channel microtube design places 10 internal channels inside each cooling tube, dramatically increasing the surface area contact between the engine oil and the tube wall compared to a standard single-channel tube. Combined with the 14 percent larger core thickness (32mm vs OEM 28mm), this cooler provides meaningfully more oil cooling capacity than the factory unit under the same coolant flow conditions.

Yes. The 8372 fits the BMW G20 M340i (2019 and newer), G22 M440i (2021 and newer), and G42 M240i (2022 and newer) equipped with the B58 engine and the factory oil cooler. These three platforms share the same B58 engine architecture and factory oil cooler mounting provisions when the MEP option is present.

CSF does enforce MAP pricing on select products including this oil cooler. Confirm current pricing at your authorized CSF retailer.

Yes. The larger core and improved microtube geometry provide more thermal headroom than the factory BMW oil cooler, which is particularly beneficial during track sessions where sustained high-RPM and high-load operation can push B58 oil temperatures beyond the optimal range. Lower oil temperatures reduce viscosity breakdown and protect engine components over extended track sessions.

Yes. Because the engine oil cooler on the B58 is integrated with the engine coolant circuit, the coolant system must be partially drained to remove and replace the cooler. Refer to the BMW repair manual for the proper coolant drain procedure for your specific chassis before beginning installation.

CSF backs the 8372 with their standard manufacturer warranty covering defects in materials and workmanship. Contact CSF or your authorized retailer to confirm current warranty terms before purchase.

Installation Instructions

1. Allow the engine to cool completely before beginning. The oil cooler is integrated with the engine coolant circuit and operates at pressure when warm.
2. Disconnect the negative battery terminal.
3. Place a coolant catch pan under the engine. Partially drain the cooling system by removing the lower radiator hose or drain plug per the BMW repair manual procedure for your chassis.
4. Locate the engine oil cooler on the B58 engine block. The unit is accessible from the top of the engine bay on G20, G22, and G42 chassis.
5. Disconnect the coolant inlet and outlet hoses from the OEM oil cooler. Use hose clamp pliers to release the spring clamps.
6. Remove the oil cooler mounting hardware and carefully lift the OEM unit out. Have a rag ready as residual oil and coolant will drain from the ports.
7. Install this oil cooler into the mounting location using the factory hardware. Ensure the inlet and outlet ports are oriented correctly per the OEM unit orientation.
8. Reconnect the coolant hoses and seat all spring clamps securely. Verify both hoses are fully seated on the port necks.
9. Refill the cooling system with BMW-specified coolant mixture per the G20/G22/G42 service manual. Perform the coolant bleeding procedure to purge air from the system.
10. Reconnect the battery, start the engine, and bring to operating temperature. Check for coolant or oil leaks at all connections. Top off coolant as needed once the system has been bled.