Mercedes W415 109CDI Diesel Engine Cooling Thermostat Housing 170741R

Mercedes W415 109CDI Diesel Engine Cooling Thermostat Housing is a component from the Thermostats and housings category, designed for the diesel engine cooling system in the Mercedes W415 109 CDI model. This used housing ensures a factory-fit for the power unit, which facilitates servicing and reduces the risk of compatibility issues. It is a practical solution for workshops and users looking for a proven component at a reasonable price.

Specifications and technical data

• SKU: 170741R
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: 170741R
• Substitutable numbers: 170741R
• Location on the vehicle: Front
• Fuel type: Diesel
• Category: Thermostats & Housings

Purpose and function in the cooling system

The thermostat housing in the Mercedes W415 109 CDI is responsible for the stable seating of the thermostat and the proper routing of coolant in the front part of the vehicle. A correctly selected component helps maintain the optimal operating temperature of the diesel engine, which translates into smooth engine operation, reduced fuel consumption, and less strain on other cooling system components.

In the case of diesel engines, maintaining stable thermal parameters is particularly important, which is why using the original housing design is beneficial for both engine durability and operational comfort. Precise fitment for the specific body version and power unit minimizes the risk of leaks and installation problems.

Construction, installation, and positioning

The thermostat housing in this Mercedes model is mounted in the front part of the engine bay, which facilitates service access and shortens replacement time. The design intended for the diesel unit ensures proper routing of coolant channels and cooperation with other system elements, such as hoses, the radiator, or the water pump.

The main advantages of this solution include:

• factory fitment for the diesel engine architecture in the Mercedes W415 109 CDI,
• preservation of the original coolant flow geometry,
• easier installation thanks to the manufacturer-intended positioning at the front of the vehicle,
• suitability for standard service procedures without the need for installation modifications.

For workshops, this means a repeatable, predictable installation process, and for the user – a lower risk of failures resulting from an incorrectly fitted replacement part.

Application in a diesel engine

Mercedes diesel engines, such as the 109 CDI unit, operate under specific thermal conditions that require a stable and efficient cooling system. The thermostat housing dedicated to the diesel version is designed taking into account the thermal characteristics of these types of units, which helps maintain the appropriate operating temperature under various load conditions.

A properly functioning thermostat together with a matched housing:

• accelerates reaching operating temperature after start-up,
• stabilizes temperature during city and highway driving,
• reduces the risk of engine overheating or undercooling,
• supports uniform lubrication and longer service life of the power unit.

Benefits of using the original thermostat housing

Choosing a thermostat housing designed specifically for the Mercedes W415 109 CDI allows for maintaining consistency with the vehicle's factory design. Original geometry and mounting points facilitate installation and cooperation with existing hoses and engine accessories. For the user, this means a lower risk of coolant leaks and stable system operation in the long term.

A used component can be a good choice in situations where the cost-to-functionality ratio is important, while maintaining compliance with the manufacturer's factory specifications. This solution is often chosen by workshops specializing in the service of commercial and fleet vehicles, where repair repeatability and predictability are key.

Expanding cooling system service

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other elements from the same group, such as additional housings, bodies, or components working with the thermostat, check the available parts in the Mercedes Thermostats and housings category.

For users interested in comparing solutions used in different brands and engine versions, including sports variants, an article discussing the differences in the construction of power units and chassis may be helpful – check the analysis of Audi RS models against standard versions to better understand the importance of properly selected components in the drivetrain and cooling system.