CSF 3725 Radiator - Front

CSF 3725 Radiator for BMW Cooling Service

The CSF 3725 radiator is an OE-style replacement built with an aluminum core and plastic tanks for BMW cooling system service. It is engineered with a cross-flow layout and quick-connect inlet and outlet pipes to match the factory-style connection points on supported BMW applications.

Key Features

• Aluminum core with plastic tank construction
• Cross-flow radiator design
• 1-row core configuration
• 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
• Cap not included
• CSF part number 3725

Detailed Description

CSF part number 3725 is a radiator designed for BMW vehicles that use the listed cross-flow cooling layout. The aluminum core helps transfer heat efficiently, while the plastic tanks follow an OE-style construction commonly used in factory cooling systems. CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind-tunnel testing. This radiator is a direct-fit style solution for BMW 320i, 328i, 335i, 428i, and 435i applications listed below.

This part cross-references Bosch 13394 for the same application.

What It Helps Address

• Coolant leaks from a cracked or aging radiator tank
• Restricted cooling performance from a worn factory radiator
• Overheating caused by reduced heat exchange efficiency
• Fitment issues when replacing an OE-style BMW radiator
• Cooling system service on BMW 320i, 328i, 335i, 428i, and 435i models

Fitment

• Fits 2015-2017 BMW 320i, N/A, w/o SULEV
• Fits 2014-2016 BMW 428i, Front
• Fits 2014-2016 BMW 435i, Front
• Fits 2015 BMW 335i, N/A, w/o SULEV
• Fits 2012-2014 BMW 328i, N/A, w/o SULEV

Installation Notes and Tips

Verify inlet and outlet orientation before installation, since this radiator uses a left-side inlet and right-side outlet. Confirm the vehicle is not equipped with SULEV where noted in the fitment data, and compare the existing radiator core dimensions and quick-connect pipe style to the replacement part before assembly.

Quality Assurance

CSF states that its factories are ISO/TSO certified and that its radiators are engineered and tested for cooling performance validation. The brand has supplied radiators worldwide for decades and manufactures a broad range of applications for leading vehicle platforms.