Denso 221-3124 Radiator

Denso 221-3124 Radiator for Toyota 4Runner

Denso 221-3124 is a radiator built for 2003-2009 Toyota 4Runner applications. It matches OE-style fitment requirements with the core dimensions, inlet and outlet sizing, and integrated transmission oil cooler needed for proper engine temperature control.

Key Features

• Fits 2003-2009 Toyota 4Runner
• Core height: 25.5620 in.
• Core width: 23.2500 in.
• Core thickness: 1.4370 in.
• 1.5000 in. inlet and 1.5000 in. outlet diameters
• Transmission oil cooler included
• OE-focused radiator configuration for direct replacement use

Detailed Description

This Denso radiator, part number 221-3124, is engineered to meet the dimensional and functional requirements expected in Toyota 4Runner cooling systems. Denso supplies radiators to OE vehicle manufacturers worldwide, and this unit reflects that experience through its tank design, fin pitch, core dimensions, and material selection. For drivers searching for a radiator for a 2003-2009 Toyota 4Runner, 221-3124 provides the cooling capacity and transmission-fluid heat exchange support needed for everyday driving and demanding conditions.

As a direct-fit radiator for Toyota 4Runner models from 2003 through 2009, this unit is built for consistent engine cooling performance and reliable fitment. The included transmission oil cooler helps manage heat in vehicles equipped with automatic transmission cooling through the radiator assembly. Denso 221-3124 is also cross-referenced to Toyota 16400-50300 for the same application.

What This Radiator Helps Address

• Engine overheating caused by a worn or restricted radiator
• Coolant leaks from aging radiator tanks or seams
• Reduced cooling efficiency from damaged core passages
• Transmission fluid temperature control concerns in radiator-equipped systems
• Fitment issues when replacing the original Toyota 4Runner radiator

Installation Notes and Tips

Verify inlet and outlet hose sizes before installation and confirm the radiator matches the original core dimensions for your vehicle. Inspect hoses, clamps, and coolant condition during replacement, and flush the cooling system if contamination or debris is present. This radiator is listed for 2003-2009 Toyota 4Runner applications only, so confirm year and vehicle configuration before ordering.

Quality Assurance

Denso subjects its radiators to durability and function testing to support OE-level performance and fitment. The brand’s OE supply background and validation process help ensure dependable cooling performance under normal and demanding operating conditions.