CSF 3717 Radiator

OE-Style BMW Radiator for Cooling Performance

CSF 3717 is an OE-style radiator built with a plastic tank and aluminum core for BMW applications that need direct-fit cooling system service. It is engineered as a cross flow radiator with quick-connect inlet and outlet connections, plus a supplied Cooling Circuit control sleeve for the listed vehicles.

Compatible With BMW Z4, X1, 135i, 135is, 335i, 335i xDrive, 335is, and 335xi applications across the listed model years, this radiator follows the original layout for straightforward replacement. The CSF 3717 part number is also referenced by common interchange numbers for the same application.

Key Features

• OE-style plastic tank and aluminum core construction
• 1-row core design for factory-style cooling system replacement
• Cross flow radiator layout
• Core dimensions: 23 5/8 in. length, 13 5/8 in. width, 1 1/4 in. thickness
• 1 1/2 in. left inlet and 1 1/2 in. right outlet
• Quick-connect inlet and outlet pipe design
• Supplied with Cooling Circuit control sleeve
• No radiator cap included

Product Details

CSF builds this radiator to high-performance manufacturing standards using an aluminum core paired with plastic tanks, matching the OE-style configuration used on the supported BMW platforms. The design is wind-tunnel tested for cooling performance validation and produced by a manufacturer with ISO/TSO-certified factories and broad radiator coverage across many vehicle lines. For shoppers comparing BMW radiator replacement options, CSF 3717 is a direct-fit solution for maintaining the original cooling system layout on BMW Z4, BMW X1, BMW 135i, and BMW 335i-family vehicles.

This part cross-references Spectra Premium CU2941 and Anchor 2941 for the same application.

What It Helps Address

• Coolant leaks from aging plastic tank and core assemblies
• Reduced cooling efficiency from a worn or clogged radiator
• Overheating concerns during stop-and-go or highway driving
• Cracked inlet or outlet connections on the original radiator
• Service replacement for BMW cooling system maintenance

Installation Notes and Tips

Verify inlet and outlet orientation before installation: this radiator uses a left-side inlet and right-side outlet. Confirm the vehicle’s OE-style control sleeve requirement and inspect hoses, clamps, and adjacent cooling components before reassembly. Because the radiator uses quick-connect fittings, make sure the connections are fully seated and locked according to factory service procedures.

Quality Assurance

CSF manufactures radiators in ISO/TSO-certified facilities and validates cooling performance through laboratory testing. The brand has supplied radiators worldwide for more than 50 years and offers extensive model coverage across major vehicle applications.