Mercedes W204 Diesel OM651 Engine Coolant Thermostat Temp Sensor A6512002800

Mercedes W204 Diesel OM651 Engine Coolant Thermostat Temp Sensor is an original cooling system component from the Thermostats and housings group, designed for OM651 diesel engines. Precisely calibrated operating characteristics and integrated coolant temperature measurement support stable, safe, and economical engine performance.

Specifications and technical data

• SKU: A6512002800-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6512002800
• Substitutable numbers: A6512002800, A 651 200 28 00, A0009050600, A 000 905 06 00
• Fuel type: Diesel
• Category: Thermostats & Housings

Purpose and function in the cooling system

The presented thermostat with a temperature sensor is a component that controls the flow of coolant in the OM651 diesel engine used in Mercedes W204 class models. It is responsible for maintaining the optimal operating temperature range, which directly impacts engine performance, fuel consumption, and component durability.

Thanks to the integrated temperature sensor, the vehicle's control system receives accurate information about the current thermal state of the engine, which enables precise management of fan operation, fuel dosing, and engine protection strategies.

Key technical advantages

• Dedicated application for OM651 diesel engines, ensuring the correct opening and closing characteristics of the cooling circuit.
• Integrated coolant temperature measurement, supporting the proper operation of the engine control unit.
• Original Mercedes brand origin, which translates into geometric fit and compatibility with factory equipment.
• Suitable for use in diagnostics and repairs of the cooling system and engine thermal management.

Application in OM651 Diesel engines

OM651 diesel engines are designs with advanced thermal control, and a properly functioning thermostat with a temperature sensor is essential for:

• maintaining a stable operating temperature under variable loads,
• reducing the risk of engine overheating or underheating,
• cooperating with exhaust emission reduction systems typical for modern diesel engines.

Selecting a component from the correct Thermostats and housings group is particularly important for diesel units, where improper cooling system operation can lead to a drop in performance and increased fuel consumption.

Condition and installation aspects

The offered item is a used part, which allows for an economical repair of the cooling system while maintaining the manufacturer's original specifications. Before installation, it is recommended to perform a standard leak test and check the electrical connections of the temperature sensor to ensure proper cooperation with the vehicle's wiring.

Replacing the thermostat with a temperature sensor in the OM651 engine is a standard service procedure performed in cases of incorrect temperature readings, excessively long engine warm-up times, or symptoms of overheating. Using an original Mercedes component facilitates installation and reduces the risk of compatibility issues.

Cooling system expansion and selection of related components

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

Summary

Mercedes W204 Diesel OM651 Engine Coolant Thermostat Temp Sensor is a practical service solution for diesel engine users who want to restore proper cooling system operation while maintaining factory parameters. The original Mercedes brand origin, dedicated application for OM651 diesel units, and the integration of thermostat and temperature sensor functions make it a solid foundation for professional cooling system repair in W204 class vehicles.