1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your Denso Radiator model 221-4406. Adhering to these instructions will help ensure optimal performance and longevity of the product. This radiator is designed for specific vehicle applications to efficiently dissipate heat from the engine's coolant, maintaining proper operating temperatures.
2. Safety Information
Always prioritize safety when working with automotive components. Failure to follow safety precautions can result in personal injury or damage to the vehicle.
- Wear appropriate personal protective equipment: This includes safety glasses, gloves, and protective clothing.
- Allow engine to cool: Never attempt to work on the cooling system when the engine is hot. Pressurized hot coolant can cause severe burns.
- Handle coolant with care: Automotive coolant is toxic. Avoid skin contact and ingestion. Dispose of used coolant responsibly according to local regulations.
- Disconnect battery: Before beginning any installation, disconnect the vehicle's battery to prevent electrical hazards.
- Secure vehicle: Ensure the vehicle is safely supported on jack stands if raised.
3. Product Overview
The Denso Radiator 221-4406 is a critical component of your vehicle's engine cooling system. It features a robust design for efficient heat exchange.

This image displays the Denso Radiator 221-4406, featuring its aluminum core with numerous cooling fins, black plastic upper and lower tanks, and connection points for coolant hoses and a radiator cap.
Key components include:
- Core: The main body consisting of tubes and fins where heat exchange occurs.
- Tanks: Upper and lower reservoirs that hold coolant and connect to the engine via hoses.
- Inlet/Outlet Connections: Ports for coolant hoses.
- Radiator Cap: Maintains pressure within the cooling system.
- Drain Plug: Located at the bottom for coolant drainage.
4. Setup and Installation
Installation of a radiator requires mechanical knowledge and specialized tools. It is highly recommended that installation be performed by a qualified automotive technician.
4.1. Pre-Installation Checks
- Verify Part: Confirm that the Denso Radiator 221-4406 is the correct replacement part for your vehicle's make, model, and year.
- Inspect for Damage: Carefully inspect the new radiator for any shipping damage, such as bent fins, cracked tanks, or damaged connections. Do not install a damaged radiator.
- Gather Tools: Ensure all necessary tools and equipment are available, including a drain pan, wrenches, pliers, and a torque wrench.
4.2. Installation Steps (General Guidelines)
- Drain Coolant: With the engine cool, place a drain pan under the radiator and open the drain plug to completely drain the old coolant.
- Remove Hoses and Connections: Disconnect the upper and lower radiator hoses, transmission cooler lines (if applicable), and any other sensors or connections attached to the old radiator.
- Remove Mounting Hardware: Unbolt or unclip the old radiator from its mounting points.
- Remove Old Radiator: Carefully lift the old radiator out of the engine bay.
- Install New Radiator: Position the new Denso Radiator 221-4406 into the vehicle's radiator support. Ensure it sits correctly on its mounting pads.
- Secure Mounting Hardware: Reinstall all mounting bolts and clips, tightening them to the manufacturer's specifications.
- Reconnect Hoses and Lines: Attach the upper and lower radiator hoses, transmission cooler lines, and any other connections. Use new hose clamps if the old ones are worn.
- Close Drain Plug: Ensure the radiator drain plug is securely closed.
- Refill Coolant: Fill the cooling system with the vehicle manufacturer's recommended type and amount of coolant. Use a funnel to prevent spills.
- Bleed Air: Start the engine and allow it to reach operating temperature with the heater on full. Monitor the coolant level and add more as needed to remove any trapped air from the system. This process may take some time.
- Inspect for Leaks: After bleeding, thoroughly inspect all connections and the radiator itself for any signs of leaks.
5. Operating
Once installed, the Denso Radiator operates automatically as part of your vehicle's cooling system. Proper operation relies on maintaining adequate coolant levels and a functional thermostat.
- Monitor Temperature Gauge: Regularly observe your vehicle's engine temperature gauge. Consistent operation within the normal range indicates proper cooling system function.
- Check Coolant Level: Periodically check the coolant level in the overflow reservoir when the engine is cool. The level should be between the 'MIN' and 'MAX' marks.
- Avoid Overheating: If the temperature gauge indicates overheating, pull over safely, turn off the engine, and allow it to cool before inspecting the system. Do not open the radiator cap on a hot engine.
6. Maintenance
Regular maintenance is crucial for the longevity and efficiency of your Denso Radiator and the entire cooling system.
- Coolant Level Check: Check the coolant level in the overflow reservoir at least once a month. Top up with the correct coolant type if necessary.
- Coolant Flush and Replacement: Follow your vehicle manufacturer's recommendations for cooling system flush and coolant replacement intervals. This typically ranges from every 30,000 to 100,000 miles, depending on the coolant type.
- Inspect Hoses and Clamps: Periodically inspect radiator hoses for cracks, bulges, or softness. Ensure hose clamps are tight and free from corrosion.
- Radiator Fin Cleaning: Over time, debris (leaves, insects, dirt) can accumulate on the radiator fins, reducing cooling efficiency. Carefully clean the fins using compressed air or a soft brush, taking care not to bend them.
- Leak Inspection: Visually inspect the radiator, hoses, and connections for any signs of coolant leaks (e.g., colored stains, drips).
7. Troubleshooting
If you experience issues with your vehicle's cooling system, consider the following common problems and potential solutions. For complex issues, consult a qualified technician.
7.1. Engine Overheating
- Low Coolant Level: Check and top up coolant. Inspect for leaks.
- Blocked Radiator Fins: Clean radiator fins to improve airflow.
- Faulty Thermostat: A stuck closed thermostat prevents coolant circulation. Requires replacement.
- Cooling Fan Malfunction: Ensure the electric cooling fan operates when the engine is hot and the vehicle is stationary.
- Internal Radiator Blockage: Sediment or corrosion can restrict coolant flow. May require professional flushing or radiator replacement.
7.2. Coolant Leaks
- Loose Hose Clamps: Tighten or replace clamps.
- Damaged Hoses: Replace cracked, brittle, or bulging hoses.
- Radiator Damage: Inspect the radiator core and tanks for punctures, cracks, or corrosion. Small leaks might be repairable with specialized products, but significant damage usually requires radiator replacement.
- Faulty Radiator Cap: A cap that doesn't hold pressure can lead to coolant loss. Test or replace the cap.
8. Specifications
| Specification | Detail |
|---|---|
| Brand | Denso |
| Model Number | 221-4406 |
| OEM Part Number | 2214406 |
| UPC | 042511203532 |
| Item Weight | 9.93 pounds |
| Item Package Length | 34.53 inches |
| Item Package Weight | 15.02 pounds |
| Country Of Origin | UNITED STATES |
| Exterior Finish | Machined |
| Fuel Type Compatibility | Gasoline |
| Product Grade | Performance Part |
| Fit Type | Vehicle Specific |
9. Warranty Information
Denso products are manufactured to high-quality standards. For specific warranty terms and conditions, please refer to the official Denso warranty statement provided with your purchase or visit the official Denso website. Keep your proof of purchase for any warranty claims.
10. Support
If you require further assistance, have questions regarding installation, or need to troubleshoot an issue not covered in this manual, please contact Denso customer support or consult a certified automotive technician.
For more information, you may visit the official Denso website: www.denso.com





