Mercedes W202 W203 W210 M111 Coolant Thermostat Housing A1112030573

Mercedes W202 W203 W210 M111 Coolant Thermostat Housing is a component from the Thermostats and housings category, designed for the cooling system of M111 series engines in Mercedes W202, W203, and W210 class models. This original used housing ensures a factory-fit to the power unit and allows for the restoration of proper coolant circulation without the need for aftermarket replacements.

Specifications and technical data

• SKU: A1112001303-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1112001303
• Substitutable numbers: A1112001303, A 111 200 13 03, A1112030573, A 111 203 05 73, A0005426218, A 000 542 62 18, BG
• Category: Thermostats & Housings

Purpose and function in the cooling system

The thermostat housing in the M111 engine is responsible for the stable seating of the thermostat and the proper routing of coolant between the engine block and other system components. A correctly selected housing minimizes the risk of leaks, supports the maintenance of the optimal operating temperature of the unit, and limits the phenomenon of engine overheating or undercooling.

In the case of Mercedes W202, W203, and W210 models, the use of the appropriate housing is particularly important due to the specific design of M111 engines and the characteristic layout of the coolant ports and channels. Using the correct component allows for maintaining compliance with the factory geometry of the system and facilitates the installation of other components.

Benefits of using an original housing

The original coolant thermostat housing for the M111 engine provides:

• factory fit to the cylinder head and cooling hoses,
• correct positioning of the thermostat relative to the flow channels,
• maintenance of the cooling system operating characteristics designed by the manufacturer,
• easier installation thanks to compatibility with factory mounting points.

For users who want to maintain the original configuration of the cooling system, using such a component is a practical solution that allows for reducing the risk of operational problems resulting from poorly fitted aftermarket replacements.

Characteristics and condition of the component

The presented Mercedes thermostat housing comes from dismantling and is offered as a used part. This type of component, while maintaining tightness and correct geometry of the contact surfaces, can be successfully used in cooling system repairs, especially in vehicles where compliance with the manufacturer's original specification is important.

The housing belongs to the Thermostats and housings group, which means it is designed to work with a thermostat suitable for a given variant of the M111 engine. Before installation, it is recommended to perform a standard inspection of the sealing surfaces and use new gaskets in accordance with the vehicle manufacturer's service recommendations.

Part selection by numbers and compatibility

The element has a dedicated OEM part number and associated interchangeable numbers, which facilitates the verification of compatibility with a specific engine version and vehicle year. When selecting the housing, it is worth comparing the markings with the service documentation or the dismantled part to ensure that the geometry of the ports, mounting points, and coolant routing method are consistent with the requirements of the given Mercedes unit.

Thanks to this, the housing can be used both for standard replacement of a worn-out part and for repairs related to cooling system leaks, ensuring consistency with the factory design of the power unit.

Related cooling system components and additional information

If you are planning a comprehensive repair or modernization of the engine area in your Mercedes and need other elements from the same group, such as housings, thermostat inserts, or connection ports, check the available parts in the Mercedes Thermostats and housings category.

When working on the cooling system, it is also worth paying attention to the general condition of the radiator, hoses, and other components responsible for dissipating heat from the engine. Additional tips regarding the diagnostics of power unit overheating and the impact of cooling system efficiency on engine durability can be found in the article Engine cooling system – overheating, repair, and used radiators.