Mercedes W204 W212 OM651 Diesel EGR Valve With EGR Exhaust Cooler A6511400775

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W204 W212 OM651 Diesel EGR Valve With EGR Exhaust Cooler is a factory-original exhaust gas recirculation component designed for OM651 diesel engines. Combining the EGR valve with an exhaust cooler ensures stable engine performance, reduced emissions, and proper thermal conditions in the cylinder head area. This solution is dedicated to Mercedes vehicles, allowing for the restoration of proper EGR system operation without interfering with the engine's construction.

Specifications and technical data

• SKU: A6511400700-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6511400775
• Substitutable numbers: A6511400700, A 651 140 07 00, A6511400775, A 651 140 07 75
• Fuel type: Diesel
• Category: Coolant Hoses

Function of the EGR valve with exhaust cooler in the OM651 Diesel engine

The integrated EGR valve with exhaust cooler is responsible for the controlled supply of exhaust gases to the intake manifold and their prior cooling. In a diesel engine, this solution:

• lowers combustion temperature, which helps reduce nitrogen oxides (NOx),
• stabilizes the operating conditions of the OM651 unit across a wide range of loads,
• reduces the risk of overheating components in the cylinder head and manifold area,
• supports the proper functioning of exhaust gas treatment systems.

By using a dedicated EGR module with an exhaust cooler, the engine control system can precisely dose the amount of recirculated gases, which translates into smoother engine operation and predictable load response.

Construction and purpose in the cooling system

The presented component belongs to the Cooling system hoses and pipes group, as the EGR exhaust cooler is integrated into the coolant circuit. The flow of fluid through the heat exchanger allows for the extraction of thermal energy from the exhaust gases before they are reintroduced into the intake. In practice, this means:

• better temperature control in the intake system area,
• lower thermal load on the manifold and EGR valve,
• more predictable operating conditions for temperature and pressure sensors.

This combination of cooling and exhaust gas recirculation functions is particularly important in modern diesel units, where precise temperature management has a direct impact on component durability and compliance with emission standards.

Benefits of using an original Mercedes component

Using an EGR valve with an exhaust cooler dedicated to Mercedes W204 and W212 models with the OM651 engine ensures:

• geometric fit to the factory manifold and cooling hoses,
• compatibility with the original engine control unit software,
• preservation of the factory operating parameters of the exhaust gas recirculation system.

The original Mercedes component minimizes the risk of assembly issues, leaks, or diagnostic errors related to incorrect flow characteristics. This is especially important in diesel engines, where the EGR system is closely linked to injection maps and exhaust gas treatment regeneration strategies.

Practical operational and diagnostic tips

When replacing the EGR valve with an exhaust cooler in a diesel unit, it is worth paying attention to:

• the condition of the coolant hoses and their tightness,
• the cleanliness of the intake channels and the absence of excessive soot deposits,
• proper bleeding of the cooling system after installation,
• checking EGR operating parameters via computer diagnostics after starting the engine.

This approach allows you to fully utilize the potential of the installed component and reduce the risk of recurring faults related to overheating or improper exhaust gas recirculation. Additional information on the impact of temperature on the cooling system and how to reasonably use used components can be found in the guide Summer heat vs. cooling system – used radiators and fans, which discusses practical aspects of operation in high temperatures.

Expansion of the system in the Cooling system hoses and pipes group

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 flexible coolant hoses, sections connecting the exhaust cooler to the cooling system, or additional return hoses, check the available parts in the Mercedes cooling system hoses and pipes category.

Summary

Mercedes W204 W212 OM651 Diesel EGR Valve With EGR Exhaust Cooler is a solution designed for diesel engines that combines exhaust gas recirculation and cooling functions in a single module. A properly selected component in the cooling and intake system allows for the restoration of correct engine operating parameters, reduction of emissions, and maintenance of stable thermal conditions during the daily operation of a Mercedes vehicle with a diesel engine.