Audi R8 42 4.2 V8 FSI Engine Coolant Radiator Cooling Unit 420121254B

Audi R8 42 4.2 V8 FSI Engine Coolant Radiator Cooling Unit is an original cooling system component, designed specifically for the V8 FSI engine in the 42 generation Audi R8. Thanks to its factory OEM design, it ensures precise fitment, stable operating parameters, and predictable performance in demanding road conditions. This is a solution for users who expect consistency with the factory cooling system design and wish to maintain the engine's original operating characteristics.

Specifications and technical data

• SKU: 420121254B
• Mark: Audi
• Condition: Used
• OEM Part Number: 420121254B
• Substitutable numbers: 420121254B, 420 121 254 B
• Part type: Radiator
• Category: Radiators

Purpose and role in the Audi R8 4.2 V8 FSI cooling system

The presented radiator belongs to the Water Radiators category and is responsible for efficiently dissipating heat from the coolant in the Audi R8 engine with the 4.2 V8 FSI unit. High heat exchange efficiency is crucial during dynamic driving, frequent acceleration, and operation in elevated ambient temperatures. Using an original component allows for maintaining a stable operating temperature, which promotes the durability of the powertrain and the proper operation of engine accessories.

Construction, fitment, and performance parameters

The radiator was designed by the vehicle manufacturer with the specific airflow and coolant flow layout of the Audi R8 in mind. This means:

• factory mounting points matched to the 42 generation body,
• core geometry and ports adapted to the stock cooling system hoses,
• compatibility with original fans and air guide shrouds.

As a result, installation is straightforward, without the need for modifications, and the system retains the flow characteristics designed by Audi engineers. The used OEM component is a good choice for users who want to restore the factory configuration after a collision, failure, or cooling system upgrade.

Condition, verification, and service application

The offered radiator is a used component, which allows for economical repair while maintaining the original design. This type of component is particularly useful in situations where mechanical damage has occurred (e.g., after a front-end impact) or when there is a need to replace a worn radiator to restore the proper efficiency of the cooling system. Before installation, it is recommended to perform a standard leak test and check the external condition, in accordance with good service practices when working with used parts.

Benefits of using an original Audi water radiator

Using a factory radiator in the Audi R8 4.2 V8 FSI brings a number of practical benefits:

• Replication of factory operating parameters – maintaining the stock engine operating temperature characteristics.
• Consistency with other cooling system components – no need to adapt hoses, mounts, or shrouds.
• Predictable behavior under high load conditions – essential for the dynamic operation of a sports car.
• Possibility of use in post-accident repairs and comprehensive front-end restoration.

This solution is particularly attractive for workshops specializing in the Audi brand and owners who want to keep the vehicle in a configuration close to factory condition, without experimenting with aftermarket parts of uncertain parameters.

Related cooling system components and additional technical materials

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 radiators, coolant hoses, or mounting hardware, check the available parts in the Audi Water Radiators category.

To better understand the symptoms of engine overheating, common faults, and best practices when replacing a radiator, it is worth reading our guide: Engine cooling system – overheating, repair, and used radiators. The article discusses the impact of an efficient cooling system on engine longevity and the practical aspects of selecting used radiators for premium class cars.