Volkswagen Tiguan 5N Passat Audi Q2 Q3 Water Coolant Hose Pipe Line 04L122157S

Volkswagen Tiguan 5N Passat Audi Q2 Q3 Water Coolant Hose Pipe Line is an original cooling system component from the Volkswagen Group, designed for the precise routing of coolant between engine sub-assemblies. Thanks to its factory geometry and fitment, it ensures stable system operating parameters, which translates into a safe engine operating temperature and predictable vehicle behavior under various operating conditions.

Specifications and technical data

• SKU: 04L122157S
• Mark: Volkswagen
• Condition: Used
• OEM Part Number: 04L122157S
• Substitutable numbers: 04L122157S, 04L 122 157 S
• Part type: Pipe
• Category: Coolant Hoses

Purpose and function in the cooling system

The water coolant hose used in Volkswagen Tiguan 5N, Passat, and Audi Q2 and Q3 models is responsible for the controlled flow of coolant between key system components. A correctly selected and installed hose:

• maintains the tightness of the coolant circuit under variable operating pressure,
• ensures stable medium flow under engine thermal load,
• minimizes the risk of localized overheating and radiator performance drops,
• reduces the possibility of leaks at connections with nozzles and fittings.

Due to its design in accordance with the vehicle manufacturer's requirements, the hose works with factory brackets and routing in the engine bay, which facilitates installation and service.

Construction and fitment for Volkswagen and Audi models

The component belongs to the Cooling system hoses and pipes group, which means it has been designed to operate in a high-temperature environment and in contact with coolant of specific chemical parameters. The shape of the hose is adapted for installation in the engine bay of Tiguan 5N, Passat, Audi Q2, and Audi Q3 models, taking into account:

• routing along factory mounting paths,
• appropriate bending radius, eliminating the risk of kinking,
• compatibility with standard clamps and quick-connectors,
• collision-free operation with engine accessories and body components.

Such fitment reduces stress on the hose material and at the connections, which promotes longer and more predictable operation.

Characteristics of the used component

The offered hose comes from dismantling and is classified as a used original component by Volkswagen. In practice, this means that it:

• retains factory geometry and mounting points,
• complies with the manufacturer's requirements regarding fitment for specific models,
• constitutes an economical alternative to new components while maintaining OEM operating characteristics.

For users looking for a reasonable compromise between repair cost and quality, such a hose allows for restoring the efficiency of the cooling system without interfering with its design.

Benefits of using an original coolant hose

Using a water coolant hose from the same manufacturer group as the vehicle translates into a number of practical benefits:

• Stable cooling system operation – maintaining the cross-section and length designed by the manufacturer supports proper fluid circulation.
• Better installation fit – no need for modifications, adjustments, or the use of additional adapters.
• Consistency with other system elements – the hose works with the standard radiator, thermostat, water pump, and other hoses.
• Reduction of secondary failure risk – proper hose routing reduces the risk of abrasion against other components in the engine bay.

Thanks to this, replacing a damaged or leaking component with an original hose allows for restoring the factory operating parameters of the cooling system in the Tiguan, Passat, and relevant Audi models.

Technical support and guide materials

When planning service work in the engine cooling area, it is worth paying attention to the completeness of the entire fluid circuit – the condition of hoses, the radiator, fans, and the quality of the coolant. The impact of high temperatures on system efficiency and the possibilities of savings when using second-hand components are described in more detail in our guide Summer heat vs. cooling system – used radiators and fans as a way to control costs, which can be a practical supplement when planning a repair.

If you are planning a comprehensive repair or upgrade of the cooling system area in your Volkswagen and need other elements from the same group, such as additional lines, hoses, or connectors, check the available parts in the Volkswagen cooling system hoses and pipes category.