Denso 221-3117 Radiator

Denso 221-3117 Radiator for Toyota 4Runner

This Denso radiator is built for 2003-2009 Toyota 4Runner applications and follows OE-style dimensions for proper cooling system fitment. Part number 221-3117 includes an integrated transmission oil cooler and is specified with 1.375-inch inlet and outlet connections.

Key Features

• Fits 2003-2009 Toyota 4Runner
• Part number 221-3117
• Core height: 25.5620 in.
• Core width: 23.2500 in.
• Core thickness: 1.0600 in.
• Inlet diameter: 1.3750 in.
• Outlet diameter: 1.3750 in.
• Transmission oil cooler included

Detailed Description

Denso 221-3117 is a replacement radiator engineered around OE specifications for the Toyota 4Runner cooling system. Denso supplies radiators to vehicle manufacturers worldwide, and this unit reflects that OE-focused experience through controlled core dimensions, tank design, fin pitch, and material selection. For drivers searching for a 2003-2009 Toyota 4Runner radiator, this part provides the correct fitment profile for direct replacement service.

The radiator’s 25.5620-inch core height, 23.2500-inch core width, and 1.0600-inch core thickness support the cooling capacity expected for this application. With a built-in transmission oil cooler, part number 221-3117 also addresses automatic transmission fluid heat management within the same assembly. This makes it a practical choice for Toyota 4Runner cooling system repair, radiator replacement, or maintenance after leaks, overheating, or age-related wear.

This part cross-references Toyota 16400-31350 and 16400-31351 for the same application.

What This Radiator Helps Address

• Coolant leaks from a damaged or corroded radiator
• Engine overheating caused by reduced heat transfer
• Transmission fluid temperature concerns tied to the radiator cooler circuit
• Restricted cooling performance from worn internal passages or fins
• Fitment issues when replacing the original Toyota 4Runner radiator

Installation Notes and Tips

Verify inlet and outlet hose sizes before installation and compare the original radiator to Denso 221-3117 for mounting points, cooler line routing, and overall dimensions. Flush the cooling system, inspect hoses and clamps, and check the radiator cap, thermostat, and coolant condition before final assembly. After installation, refill with the correct coolant specification and bleed air from the system according to Toyota service procedures.

Quality Assurance

Denso builds this radiator to meet OE manufacturer standards for configuration, durability, and function. Each radiator is tested for performance and reliability so it can handle demanding operating conditions in the Toyota 4Runner cooling system.