Audi RS4 B7 4.2 FSI Water Pump Thermostat Coolant Housing 079121115E

Audi RS4 B7 4.2 FSI Water Pump Thermostat Coolant Housing is an original cooling system component from the Thermostats and housings group, designed for operation in the demanding 4.2 FSI engine. The use of the factory Audi solution ensures stable thermal parameters of the power unit, which translates into safe operation and predictable engine behavior across the full load range.

Specifications and technical data

• SKU: 079121115E
• Mark: Audi
• Condition: Used
• OEM Part Number: 079121115E
• Substitutable numbers: 079121011Q, 079 121 011 Q, 079121115E, 079 121 115 E
• Part type: Thermostat Assembly
• Category: Thermostats & Housings

Purpose and function in the cooling system

The presented water pump with thermostat and housing is responsible for the circulation of coolant and the control of the operating temperature of the Audi RS4 B7 4.2 FSI engine. Integrating the pump, thermostat, and housing into a single assembly reduces the number of connections, minimizes the risk of leaks, and facilitates the servicing of the entire module. A properly functioning pump and thermostat assembly helps maintain a stable operating temperature, which is important for the durability of the power unit, maintaining power, and the correct operation of control systems. For high-power engines such as the 4.2 FSI, using an original Audi solution helps reduce the risk of overheating and uneven temperature distribution in the block.

Construction of the water pump – thermostat – housing assembly

The module combines several key functions in one housing: forcing the circulation of coolant, controlling its flow depending on the temperature, and distributing the medium to the appropriate channels in the engine and radiator. This design promotes the maintenance of factory flow geometry, which is essential at high rotational speeds and high thermal loads. The original Audi solution ensures a perfect fit for factory connectors, hoses, and mounts, which facilitates installation and reduces the need for additional adapters. As a result, the entire cooling system maintains the flow and venting characteristics designed by the manufacturer.

Benefits of using an original Audi component

Using the factory water pump, thermostat, and housing assembly in the Audi RS4 B7 4.2 FSI allows for consistency with the other cooling system components. Proper fitment to the engine and accessories minimizes the risk of leaks, incorrect drive belt tension, or installation errors resulting from dimensional differences. Key advantages include, among others:

• factory fitment for the 4.2 FSI unit and the Audi RS4 B7 cooling system,
• maintenance of the designed thermostat opening and coolant circulation characteristics,
• compatibility with original mounts and cooling hoses,
• reduction of the risk of engine overheating or underheating during dynamic driving.

Condition, origin, and service application

The component comes from the Audi line and is classified as used, which allows for economical repair while maintaining the original design of the cooling system. This type of part is suitable both for standard replacement of a worn module and for comprehensive engine maintenance, e.g., during an engine overhaul or major accessory service. Because the product belongs to the Thermostats and housings group, it can be treated as a central element of work related to refreshing the cooling system – especially in cars operated under conditions of increased thermal load, typical for RS models.

Support with selection and system expansion

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 housings, bodies, or thermostat assemblies, check the available parts in the Audi Thermostats and housings category. To better understand the advantages of using original components, including used OEM parts, it is worth reading the material describing quality and safety issues – you will find it in the article Quality assurance and OEM safety – why are used original car parts the best choice for your car?.