BMW Z4 E85 Engine Cooling Radiator Water Coolant Unit 5B5C870

BMW Z4 E85 Engine Cooling Radiator Water Coolant Unit is an original cooling system component designed for efficient heat dissipation from the engine unit. Thanks to its factory design, BMW ensures a stable engine operating temperature, which translates into durability and safe, predictable operation. It is a practical solution for users looking for a proven, OEM-compliant water radiator for their roadster.

Specifications and technical data

• SKU: 5B5C870
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 5B5C870
• Substitutable numbers: 17115B5C870, 5B5C870, 17119071517, 9071517
• Part type: Radiator
• Category: Radiators

Purpose and function in the cooling system

The water radiator in the BMW Z4 E85 is responsible for intensive heat exchange between the coolant and the air flowing through the core. A correctly selected component from this group allows for maintaining a stable engine operating temperature both in city traffic and during dynamic highway driving. Using an original BMW design reduces the risk of overheating, performance drops, and accelerated wear of engine components.

Benefits of using an original BMW radiator

Choosing a factory water radiator for the BMW Z4 E85 ensures:

• precise fitment for cooling system mounts and hoses,
• heat exchange surface area consistent with the manufacturer's design,
• stable operating parameters across a wide range of engine loads,
• compatibility with other system components, such as the water pump or thermostat. As a result, the engine cooling system retains its factory characteristics, and installation does not require modifications or structural compromises.

Condition of the component and practical application

The offered BMW water radiator comes from the secondary market, which allows for combining reasonable cost with maintaining the manufacturer's original specifications. It is a good solution for post-accident repairs, replacement after leaks, or restoring the car to full efficiency after overheating. A used OEM component is particularly attractive to drivers who want to maintain component consistency in their BMW Z4 E85 without resorting to aftermarket replacements with uncertain parameters.

Technical support and knowledge about the cooling system

To better understand the impact of a functional radiator on engine longevity and the symptoms of overheating, it is worth checking out our guide: Engine cooling system – overheating, repair, and used radiators. The article helps to assess when a radiator replacement is justified and how to select the right component based on solutions used in various models.

Related items in the BMW Water Radiators category

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other components from the same group, such as auxiliary radiators, cooling hoses, or expansion tanks, check out the available parts in the BMW Water Radiators category. If the repair of your BMW Z4 E85 is related to a collision or a wider range of body and mechanical work, our guide on economical car restoration using original components may also be helpful: repairing a car after a crash using used OEM parts. This makes it easier to plan your budget and select the correct cooling system components and other vehicle systems.