Mercedes W221 Engine Cooling Radiator Coolant Water Unit A2215002403

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W221 Engine Cooling Radiator Coolant Water Unit is a cooling system component designed for efficient heat dissipation from the engine, which translates into stable operating temperatures and safe thermal load. This component, intended for installation in the rear part of the vehicle, allows for maintaining cooling system efficiency at a level consistent with the design requirements of the premium class. Thanks to the original design for the Mercedes brand, this is a solution that ensures proper fitment and predictable performance during operation.

Specifications and technical data

• SKU: A2215003103-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2215003103
• Substitutable numbers: A2215003103, A 221 500 31 03, A2215002403, A 221 500 24 03
• Location on the vehicle: Rear
• Category: Radiators

Purpose and function in the cooling system

The presented water radiator is a component of the engine cooling system in the Mercedes S-Class W221 generation. Its task is the effective heat exchange between the coolant and the environment, which reduces the risk of engine overheating during city driving, highway driving, and under higher loads.

The placement in the rear part of the vehicle allows for optimal routing of cooling hoses and integration with other system components, such as pipes, the coolant pump, or the expansion tank. As a result, the entire system operates coherently, and the temperature distribution in the vehicle remains predictable.

Construction and fitment for Mercedes W221

The water radiator has been designed specifically with the body architecture and powertrain of the Mercedes W221 in mind. This means appropriately selected connection geometry, proper placement of mounts, and compatibility with factory cooling hose routing. Such fitment facilitates installation and limits the need for system modifications.

Thanks to a design consistent with the solutions used by the vehicle manufacturer, coolant flow stability and the proper heat exchange surface are maintained. This is crucial for maintaining nominal engine operating parameters, especially in luxury cars, where the cooling system must meet high standards of comfort and reliability.

Condition, application, and benefits of installation

The offered water radiator is in used condition, making it an attractive alternative to new components while maintaining the original design specifications. Choosing such a solution allows for reducing repair costs while maintaining compliance with the factory cooling system design.

By installing this component in your Mercedes W221, you can:

• restore the proper efficiency of the cooling system after a failure or leak,
• maintain engine operating parameters within the range provided by the manufacturer,
• preserve technical consistency with other vehicle components.

This solution is particularly beneficial for comprehensive cooling system maintenance when you want to combine rational costs with maintaining the original operating characteristics.

Mercedes water radiators – expansion and modernization

If you are planning a comprehensive repair or modernization of the engine area in your Mercedes and need other elements from the same group, such as additional cooling modules, auxiliary heat exchangers, or related coolant hoses, check the available parts in the Mercedes water radiators category.

Technical support and knowledge about the cooling system

To better understand how to properly diagnose engine operating temperature problems and when replacing the water radiator is justified, it is worth reaching for specialized materials. Practical tips regarding overheating, service, and selecting used components can be found in the article Engine cooling system – overheating, repair, and used radiators.

If you are interested in a broader context of using used components in premium cars, including the Mercedes brand, the material describing current market trends for parts may also be helpful: Crisis in the new parts market? Why in 2026 used originals for premium cars (BMW, Mercedes, Porsche) are the hottest trend.