CSF 3757 Radiator

CSF 3757 Radiator for Kia Optima and Hyundai Sonata

The CSF 3757 radiator is an OE-style replacement built with an aluminum core and plastic tanks for direct-fit cooling system service. It is engineered for the 2011-2015 Kia Optima and 2011-2014 Hyundai Sonata, with cross-flow construction and a single-row core layout.

Key Features

• Aluminum core with plastic tanks for OE-style construction
• Cross-flow radiator design with 1-row core
• Core dimensions: 18 5/16 in. length, 18 1/4 in. width, 7/8 in. thickness
• Inlet: 1 3/8 in. right; outlet: 1 3/8 in. left
• High-efficiency plate-type oil cooler integrated into the radiator
• Cap not included; CSF cap number 4503
• Direct replacement reference: CSF 3757

Detailed Description

CSF 3757 is a radiator assembly designed for direct replacement in select midsize Hyundai and Kia applications. It uses an OEM-style plastic tank and aluminum core construction, with inlet and outlet placement arranged for the listed vehicle fitments. The radiator also includes a high-efficiency plate-type oil cooler section and is built to CSF’s performance-focused manufacturing standards. This part cross-references Spectra Premium CU13189 for the same application.

Fits 2011-2015 Kia Optima and 2011-2014 Hyundai Sonata, with fitment coverage matching the listed model years for each vehicle. If you are replacing a leaking or restricted radiator on a Kia Optima or Hyundai Sonata, CSF 3757 provides the correct core layout and connection sizing for those applications.

Common Problems This Radiator Can Address

• Coolant leaks from a cracked or aging radiator tank
• Overheating caused by reduced heat transfer through the core
• Restricted coolant flow from internal corrosion or debris
• Transmission cooling concerns on vehicles using an integrated oil cooler
• Fitment issues when replacing a damaged OE-style radiator

Installation Notes and Tips

Verify inlet and outlet orientation before installation: inlet is on the right and outlet is on the left. Confirm the vehicle uses the listed cross-flow configuration and compare core dimensions to the original unit before removal. Transfer any required sensors or related components from the original radiator if your vehicle setup calls for them, and inspect hoses, clamps, and mounts for wear during replacement.

Quality Assurance

CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind-tunnel testing. The brand has produced radiators for more than 50 years and supplies a wide range of applications across major vehicle platforms.