Audi A3 8P A4 S4 B8 Water Pump Coolant Regulator Thermostat 1.8 TFSI 06H121026DC

Audi A3 8P A4 S4 B8 Water Pump Coolant Regulator Thermostat 1.8 TFSI is an original cooling system component from the Water Pumps group, designed for precise operation with the 1.8 TFSI engine. Integrating the coolant pump with the thermostat ensures stable operating conditions for the powertrain and efficient management of coolant temperature in demanding road conditions.

Specifications and technical data

• SKU: 06H121026CC
• Mark: Audi
• Condition: Used
• OEM Part Number: 06H121026CC
• Substitutable numbers: 06H121026CC, 06H 121 026 CC, 06H121026DC, 06H 121 026 DC
• Category: Water Pumps

Purpose and function in the cooling system

The presented water pump with thermostat is designed for 1.8 TFSI petrol engines used in Audi A3 8P and Audi A4 / S4 B8 models. It is responsible for the forced circulation of coolant in the engine block and cylinder head, while the integrated thermostat controls the flow opening to the radiator, allowing the engine to maintain its optimal operating temperature.

Thanks to its OEM design, the pump works with the factory engine management system, ensuring:

• stable operating temperature across the full load range,
• smooth engine warm-up after start-up,
• efficient dissipation of excess heat during highway and city driving.

Integrated construction: water pump and thermostat

Combining the coolant pump and thermostat into a single module reduces the number of connections in the system, which minimizes the risk of leaks and facilitates maintenance. The applied design is intended to work with factory cooling hoses and housing, ensuring that installation is orderly and predictable.

The module utilizes solutions typical for modern TFSI units, such as:

• a compact housing adapted to the engine bay space,
• precisely selected coolant flow channels,
• integrated connection sockets for stock hoses.

Benefits of using an original Audi pump

Using an original water pump with thermostat instead of a worn-out component allows for the restoration of proper cooling system performance. Factory fitment for the 1.8 TFSI unit reduces the risk of issues with bleeding, leaks, or incorrect thermostat opening characteristics, which can occur with low-quality parts.

Key advantages include:

• compliance with the factory engine temperature characteristics,
• predictable behavior under high-load conditions,
• easier diagnostics of potential cooling system faults.

Condition and service application

This item belongs to the used parts group, making it an attractive solution for budget repairs or restoring the functionality of a daily-driven vehicle. This type of component is particularly useful for:

• repairs following a cooling system failure,
• comprehensive maintenance of the 1.8 TFSI engine,
• restoring the factory configuration in A3 8P and A4 / S4 B8 series cars.

Expanding Audi cooling system service

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 pump modules, housings, or components working with the coolant circuit, check the available parts in the Audi Water Pumps category.

Technical support and service knowledge

When selecting consumables for modern powertrains, it is worth using reliable sources of knowledge. In the context of engine operation, cooling system interaction, and correct component selection according to manufacturer markings, the article "Fuel system – injectors, pumps, and fuel tank: maintenance and regeneration" may be helpful, as it discusses diagnostic principles, selection by factory markings, and good operational practices.

If your Audi belongs to model years that are increasingly treated as youngtimers, and you base your restoration on proven second-hand parts, it is also worth checking out the guide "The second life of a youngtimer – how used car parts rejuvenate cars from 1998–2012", which describes practical scenarios for upgrading and maintaining premium brand vehicles.