CSF 3966 Radiator

CSF 3966 Radiator for Mazda 3 and CX-30

CSF 3966 is an OE-style radiator built with a plastic tank and aluminum core for select Mazda applications. It is engineered as an upgraded heavy-duty replacement with a thicker core than the original design, making it a direct-fit option for 2019-2022 Mazda 3 and 2020-2022 Mazda CX-30 models.

Key Features

• OE-style radiator construction with plastic tanks and aluminum core
• Cross flow design with one-row core
• Core thickness: 5/8 in.
• Core dimensions: 17 in. wide x 26 9/16 in. long
• Inlet diameter: 1 5/16 in., right side
• Outlet diameter: 1 5/16 in., left side
• Upgraded heavy-duty core, 42% thicker than OEM 11 mm design
• CSF part number 3966

Detailed Description

CSF 3966 radiator is designed for drivers who need a direct replacement for the factory cooling unit in select Mazda 3 and Mazda CX-30 models. The aluminum core and plastic tank layout follows OE-style construction, while the upgraded core thickness adds capacity over the original 11 mm design. CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind tunnel testing. This part cross-references PAF3-15-200A and PAF3-15-200B for the same application.

What This Radiator Helps Address

• Overheating caused by a worn or restricted radiator core
• Coolant leaks from aging plastic tank and core assemblies
• Reduced cooling efficiency in stop-and-go driving
• Heat buildup from a damaged or corroded factory radiator
• Replacement needs for a failed Mazda 3 radiator or Mazda CX-30 radiator

Installation Notes and Tips

Fits 2019-2022 Mazda 3, N/A. Fits 2020-2022 Mazda CX-30, N/A. Verify inlet and outlet orientation before installation: inlet is on the right and outlet is on the left. Confirm all hose connections, mounting points, and cooling system components match the original radiator before installation. CSF 3966 uses a cross flow layout and does not include a radiator cap.

Quality Assurance

CSF radiators are manufactured in ISO/TSO-certified facilities and built for global OE and aftermarket use. The brand reports more than 30 million radiators sold worldwide and uses laboratory testing to validate cooling performance.