Coolant Water Hose BMW X3 F97 X4 F98 Expansion Tank Pipe Line 8073446

Coolant Water Hose BMW X3 F97 X4 F98 Expansion Tank Pipe Line is an original cooling system component designed for gasoline engines. Engineered by BMW, it ensures proper coolant flow between the expansion tank and other components, which translates into stable operating temperatures for the engine and safe vehicle operation.

Specifications and technical data

• SKU: 8073446
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8073446
• Substitutable numbers: 8073446, 64218073446
• Fuel type: Petrol
• Category: Coolant Hoses

Purpose and function in the cooling system

This hose is part of the Cooling system pipes and hoses category, responsible for transporting coolant between the expansion tank and the rest of the system. In BMW X3 F97 and X4 F98 vehicles with gasoline engines, it is responsible for:

• stable discharge and supply of coolant to the expansion tank,
• maintaining proper pressure in the cooling system,
• supporting the uniform operation of the thermostat and radiator,
• reducing the risk of engine overheating in both city and highway driving conditions.

Thanks to its factory geometry, the hose fits precisely within the engine bay, which facilitates installation and minimizes material stress during operation.

Original BMW construction and fitment

As an OEM component from BMW, the hose was designed specifically for the X3 F97 and X4 F98 platforms, taking into account the characteristics of gasoline engines. This means:

• compatibility with factory cooling system ports and connectors,
• appropriate inner and outer diameter for proper fluid flow,
• a shape matched to standard mounts and brackets in the engine bay,
• material selected for operation at elevated temperatures and in contact with coolant.

Such fitment reduces the risk of leaks, hose twisting, or rubbing against other components, which is particularly important in modern, densely packed engine bays.

Benefits of using a pre-owned OEM hose

Choosing a pre-owned, original cooling system hose for the BMW X3 F97 / X4 F98 is a solution that allows you to combine repair cost control with the preservation of factory performance parameters. Compared to many aftermarket replacements:

• the original hose maintains its factory geometry and length,
• it is designed for specific thermal and pressure loads,
• it facilitates installation without the need for system modifications.

This is especially important in cooling systems, where even minor deviations in fitment can lead to leaks, air pockets, or engine overheating.

The role of the hose in gasoline engine operation

In BMW X3 F97 and X4 F98 gasoline engines, the cooling system operates across a wide temperature range, especially during dynamic driving and in summer conditions. A functional expansion tank hose:

• supports the maintenance of a stable engine operating temperature,
• ensures proper coolant circulation under variable loads,
• helps protect the cylinder head, block, and accessories from the effects of overheating.

As a result, the entire cooling system operates more predictably, and the risk of failures related to excessive temperature is reduced.

More about the cooling system and related parts

If you are planning a comprehensive repair or upgrade of the cooling system area in your BMW and need other components from the same group, such as additional hoses, return lines, or connecting sections for the expansion tank, check out the available parts in the BMW cooling system pipes and hoses category.

To better understand how the condition of hoses, radiators, and fans affects engine safety in high temperatures, it is worth checking out the guide Summer heat vs. cooling system: used radiators and fans as a guarantee of savings, where you will find practical tips on the operation and selection of cooling system components.

If you are considering whether a new or used OEM part is the better choice for your situation, the comparison in the article New or used? A comparison of costs and quality of car parts may be helpful, as it discusses the differences in quality, durability, and cost-effectiveness of individual solutions.