CSF 3873 Radiator

OE-Style Radiator for Kia Optima

CSF 3873 is an OE-style radiator built for 2016-2020 Kia Optima applications. It uses an aluminum core with plastic tanks and a cross-flow layout to match the original cooling system design and maintain proper fitment in the engine bay.

With a 5/8-inch core thickness, 18 5/16-inch core width, and 25 1/16-inch core length, this radiator is engineered around the factory dimensions for direct replacement service. The quick-connect outlet pipe design and left-side inlet, right-side outlet configuration support a clean OE-style installation on the Kia Optima.

Key Features

• Fits 2016-2020 Kia Optima
• CSF part number 3873
• Aluminum core with plastic tanks
• Cross-flow radiator design
• 1-row core construction
• 1 3/8-inch inlet on the left side
• 1 3/8-inch outlet on the right side
• OE-style plastic tanks with aluminum core and quick-connect outlet pipe

Detailed Description

CSF 3873 is designed for drivers replacing a worn or leaking radiator in a Kia Optima from 2016 through 2020. The radiator follows the factory-style cross-flow layout and uses aluminum core construction with plastic end tanks to mirror the original cooling system configuration. CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind-tunnel testing.

This radiator cross-references TYC 13603 and Partslink KI3010163 for the same application. The part number 3873 is also associated with OE reference 25310C1150.

Common Cooling System Issues

• Coolant leaks from cracked or aged radiator tanks
• Overheating caused by restricted or damaged radiator flow
• Cooling performance loss from internal corrosion or clogging
• Fitment problems after replacing a damaged OE radiator
• Improper hose connection alignment on replacement installations

Installation Notes and Tips

Verify inlet and outlet orientation before installation: this radiator uses a left-side inlet and right-side outlet. Confirm the OE-style quick-connect outlet pipe connection matches the vehicle’s original setup on your Kia Optima. Transfer any required components from the original radiator if they are not included with the replacement unit.

Quality Assurance

CSF has manufactured radiators for more than 50 years and supplies a wide range of applications worldwide. The brand states that its factories are ISO/TSO certified and that its radiators are engineered and tested for cooling performance validation.