Audi A8 S8 D3 Auxiliary Water Pump Electric Coolant Unit Valve 4E0959617C

Audi A8 S8 D3 Auxiliary Water Pump Electric Coolant Unit Valve is an original cooling system component designed for precise fluid circulation within the engine and its accessories. Thanks to its electric control and integrated valve, it ensures stable thermal conditions, which translates into efficient engine operation and driving comfort. This solution is dedicated to users looking for a factory-spec component with predictable performance parameters.

Specifications and technical data

• SKU: RHD-4E0959617C-1
• Mark: Audi
• Condition: Used
• OEM Part Number: 4E0959617C
• Substitutable numbers: 4E0959617C, 4E0 959 617 C
• Category: Water Pumps

Purpose and function in the cooling system

The presented electric auxiliary coolant pump has been designed specifically for the Audi A8 and S8 D3 generation models. Its task is to support the main cooling circuit through forced fluid flow in selected circuits, which helps maintain a stable operating temperature for the engine and associated components.

In practice, this means more uniform heat distribution, reduction of localized overheating, and better temperature control under high load or idling conditions. The integrated valve allows for precise flow control, which is particularly important in the advanced cooling systems used in higher-end Audi models.

Construction and advantages of using an original pump

As a part of the Water pumps group, this unit combines an electric drive with a valve module, creating a compact and functional sub-assembly. The original Audi design ensures:

• perfect fitment for factory mounts and cooling system hoses,
• proper integration with the vehicle's electronics,
• maintenance of factory coolant flow and pressure characteristics.

Using an original auxiliary pump reduces the risk of compatibility issues, leaks, or control errors that may occur with aftermarket parts of uncertain origin. This is particularly important in luxury vehicles, where the cooling system is complex and tightly integrated with other systems.

Selection by part numbers and vehicle integration

The pump was developed as an OEM part, which facilitates its identification and selection based on catalog numbers and vehicle data. This allows for precise verification of compatibility with a specific version of the Audi A8 or S8 D3, minimizing the risk of purchasing an incorrect part. Proper selection is crucial for maintaining correct fluid flow, avoiding controller errors, and ensuring the stable operation of the entire cooling system.

In case of doubt, knowledge regarding diagnostics and the selection of other vehicle system components may also be useful – this is described in more detail in a blog article dedicated to the fuel system, which discusses, among other things, the selection of components by OEM and VIN numbers: Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration.

Condition, service application, and benefits of replacement

The offered auxiliary coolant pump is a used item, making it an attractive cost-effective alternative to new OEM components while maintaining the factory design. It is suitable both for standard replacement of a worn-out pump and for broader service work within the cooling system, e.g., after engine repairs or accessory upgrades.

The main benefits of using this component include:

• maintaining the proper operating temperature of the engine under various load conditions,
• support for the main coolant pump, especially in complex circuits,
• maintaining consistency with the factory Audi cooling system design.

Expanding the Audi cooling system – related components

If you are planning a comprehensive repair or upgrade of the engine area in your Audi and need other elements from the same group, such as additional pumps, fluid circulation modules, or control valves, check out the available parts in the Audi water pumps category.