BMW X5 F15 E70 X6 F16 E71 Coolant Rad Cooling Expansion Tank 8630170

The BMW X5/X6 Coolant Expansion Tank is an original cooling system component designed for BMW X5 F15, E70, and X6 F16, E71 models. This factory expansion tank ensures stable operation of the cooling system, proper fluid volume compensation, and safe pressure relief. Thanks to its precise fit for specific BMW X5 and X6 generations, it offers a functional service solution for cooling system repairs and maintenance.

Specifications and technical data

• SKU: 8630170
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8630170
• Substitutable numbers: 8630170, 17138630170, 8621092, 17138621092, 7647290, 17137647290, 7552546, 17137552546
• Category: Expansion & Overflow Tanks

Purpose and Function in the Cooling System

The offered expansion tank is a cooling system component responsible for stabilizing the pressure and level of coolant in the engine. It works in conjunction with the radiator, hoses, and other components, allowing for compensation of fluid volume changes during engine heating and cooling. A correctly selected expansion tank reduces the risk of overheating, air ingress into the system, and uncontrolled leaks.

The component is structurally adapted to the engine bay architecture of BMW X5 F15, E70, and X6 F16, E71, which facilitates installation at factory mounting points and ensures proper routing of coolant hoses.

Original Origin and Replacement Numbers

The presented tank comes from the BMW OE line, meaning it complies with the manufacturer's factory standards regarding materials, shape, and connector placement. The part has a dedicated OEM number and assigned replacement numbers, allowing for precise selection based on manufacturer markings or service catalogs. The presence of reference numbers simplifies compatibility verification with specific engine versions and vehicle model years.

Using an original expansion tank instead of universal parts helps maintain the factory operating characteristics of the cooling system and reduces the risk of fitting issues with connectors and brackets.

Condition, Service Application, and Benefits of Installation

The item is offered as a used part, providing a cost-effective solution while maintaining original BMW specifications. This type of expansion tank is suitable for both standard replacement of a worn or damaged component and for major cooling system service work, such as replacing the radiator, hoses, or coolant.

The main advantages of using an original BMW expansion tank in X5 and X6 models include:

• factory fit for the engine bay and mounting points,
• compliance with the cooling system's operating pressure parameters,
• correct placement of connectors and hose attachments,
• easier diagnosis of potential leaks due to the known OEM design.

Assistance with Selection and Technical Information

When selecting an expansion tank for BMW X5 F15, E70, and X6 F16, E71, it is crucial to compare the OEM part number and interchangeable numbers with the vehicle's documentation or the manufacturer's catalog. The product description provides markings to verify compatibility with specific equipment versions and engine units. If in doubt, it is advisable to use the vehicle's VIN or consult the technical department to ensure full installation compatibility.

For users interested in a broader context of using used parts in vehicles, including powertrain components, an expert guide may be helpful: Why Buying Used Gearboxes and Engines is Worthwhile – Facts Instead of Myths, which discusses, among other things, selection based on OEM numbers and practical aspects of optimizing repair costs.

Related BMW Cooling System Components

If you are planning a comprehensive repair or upgrade of the cooling system area in your BMW and need other parts from the same group, such as additional tanks, mounting elements, or related cooling system components, check the available parts in the BMW Expansion Tanks category.