BMW E87 E90 E91 N52 N53 Expansion Tank Heater Thermostat Line 7548223

BMW E87 E90 E91 N52 N53 Expansion Tank Heater Thermostat Line is an original cooling system component from the Cooling system hoses and pipes category, designed for use in selected BMW models with N52 and N53 engines. The product comes from dismantling, which allows for an economical yet technically correct repair of the cooling system without compromising on fitment.

Specifications and technical data

• SKU: 7548223
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7548223
• Substitutable numbers: 17127548223, 7548223, 17127521052, 7521052
• Category: Coolant Hoses

Function and application in the BMW cooling system

The presented water line is responsible for the controlled flow of coolant between the cooling system components in BMW E87, E90, and E91 series vehicles with N52 and N53 units. A properly selected water hose ensures a stable engine operating temperature, reduces the risk of overheating, and supports even heat dissipation from the engine block to the radiator.

Thanks to the factory geometry and connection diameters, the line maintains the correct routing in the engine bay, minimizing stress, twisting, and potential leaks at the joints. This is particularly important in modern BMW units, where the cooling system operates under increased pressure and at high temperatures.

Benefits of using an original BMW line

Using an original water line instead of a worn-out component brings a number of practical benefits:

• Factory fitment – maintaining the correct length, shape, and connection diameter, which facilitates installation and eliminates the need for modifications.
• Stable cooling system operation – proper coolant flow supports maintaining the optimal temperature of the power unit.
• Reduced risk of leaks – a properly selected line reduces stress on clamps and connectors, which translates into connection tightness.
• Economical repair – a part from dismantling allows for lower service costs while maintaining the original manufacturer's specifications.

For users who use their BMW intensively (city driving, highway driving, frequent engine warm-up and cool-down cycles), replacing a worn-out water line with a functional component from the same group is a reasonable investment in reliability.

Condition, origin, and technical aspects

The offered line comes from a BMW vehicle and is an original component, designed specifically for use with the N52 and N53 engine cooling systems. As a used part, it has been obtained from dismantling, which allows for the reuse of a component consistent with the factory design assumptions.

In practice, this means that:

• compatibility with factory connectors and clamps is maintained,
• the geometry of the line corresponds to the original routing in the engine bay,
• installation is possible without interfering with other cooling system components.

Such a solution is particularly beneficial for workshops specializing in the BMW brand and for conscious users who prefer parts consistent with the manufacturer's original design.

Cooling system and engine durability

A functional water line has a direct impact on the thermal safety of the power unit. Leaks, micro-cracks, or deformations of the lines can lead to coolant loss, and consequently to engine overheating. In the case of modern BMW units, such as the N52 and N53, excessively high operating temperatures can result in costly damage.

If you want to better understand how the entire cooling system affects engine longevity and what symptoms may indicate problems with coolant flow, it is worth checking out the guide on our blog: Engine cooling system – overheating, repair, and used radiators.

Complementary BMW cooling system components

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 additional water lines, flexible return hoses, or pipes supplying liquid to the radiator, check the available parts in the BMW cooling system hoses and pipes category.

Choosing a used water line from dismantling is also an environmentally friendly solution – reusing functional components reduces waste and the consumption of primary raw materials, while maintaining the functionality of the cooling system.