CSF 3708 Radiator

OE-Style BMW Cooling Replacement

This CSF radiator is built for BMW applications that need an OE-style cooling replacement with an aluminum core and plastic tanks. Part number 3708 is designed for direct-fit service on select BMW 323i, 325i, 330i, and Z4 models, with cross-flow construction and quick-connect inlet and outlet pipe connections.

CSF’s radiator line is engineered to high performance standards and validated through laboratory wind tunnel testing for cooling performance. The brand also manufactures a broad range of radiator applications for many leading vehicle platforms, including BMW fitments like this CSF 3708.

Key Features

• CSF 3708 radiator for select BMW cooling system applications
• 1-row plastic tank aluminum core design
• Cross-flow layout for OE-style packaging
• Core thickness: 1 1/4 in.
• Core dimensions: 17 5/8 in. wide x 22 13/16 in. long
• Inlet: 1 1/2 in. left; outlet: 1 1/2 in. right
• Quick-connect inlet and outlet pipe design
• Cap not included

Detailed Description

The CSF 3708 radiator uses an OE-style plastic tank and aluminum core construction to match the factory cooling layout on supported BMW models. Its cross-flow design, 1-row core, and quick-connect pipe connections are intended to maintain proper coolant routing and fitment in the engine bay while supporting stable operating temperatures. This part cross-references BMW applications commonly listed under 17 11 9 071 518 and CU2635 for the same application.

Compatible With select BMW 323i, 325Ci, 325i, 325xi, 328i, 330Ci, 330i, 330xi, 320i, 323Ci, 328Ci, and Z4 models across the listed years, this radiator is a practical replacement when the original unit is leaking, restricted, or no longer cooling efficiently. Part number 3708 is a direct-fit option for BMW owners looking for an OE-style radiator assembly.

Common Cooling System Issues

• Coolant leaks from cracked or aged radiator tanks
• Overheating caused by reduced heat transfer
• Restricted coolant flow from internal buildup or corrosion
• Temperature instability during stop-and-go driving
• Fitment problems when replacing a damaged factory-style radiator

Installation Notes and Tips

Verify inlet and outlet orientation before installation: inlet is on the left and outlet is on the right. Confirm the vehicle uses the listed OE-style quick-connect pipe arrangement and compare core dimensions, tank style, and mounting points against the original radiator before removal. Flush the cooling system, inspect hoses and seals, and refill with the correct BMW-approved coolant mixture after installation.

Quality Assurance

CSF manufactures radiators to ISO/TSO-certified factory standards and validates cooling performance through laboratory testing. The brand has supplied radiator applications worldwide for more than 50 years, with a large catalog of fitments across major vehicle platforms.