Fuel Rail Mercedes W164 W207 W212 OM642 Right Injector Pressure Line

The Mercedes W164 W207 W212 OM642 Fuel Rail is an original component of the diesel engine fuel system, designed for installation on the right side in select Mercedes models. The precise design of the rail ensures stable fuel pressure for the injectors, which translates to smooth engine operation and correct combustion characteristics.

Specifications and technical data

• SKU: A6420703095
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420703095
• Substitutable numbers: A6420703095, A 642 070 30 95
• Location on the vehicle: Right
• Category: Fuel Injectors

Purpose and Function of the OM642 Fuel Rail

The fuel rail in the OM642 engine plays a crucial role in the common rail system, responsible for storing fuel under high pressure and distributing it evenly to individual injectors. A correctly selected rail helps maintain stable system operating parameters, reduce pressure fluctuations, and supports precise fuel metering across the entire RPM range.

This component is particularly important in Mercedes diesel engines, where fueling precision affects the smoothness of operation, dynamics, noise levels, and exhaust emissions. Using a dedicated rail for the OM642 unit helps maintain the engine's factory performance characteristics.

Construction and Vehicle Placement

The presented fuel rail is designed for installation on the right side of the engine bay, in accordance with the factory architecture of the OM642 unit in Mercedes W164, W207, and W212 models. The appropriate shaping of the body and the arrangement of connection ports allow for correct routing of high-pressure lines and secure mounting to the block or cylinder head.

This structural adaptation ensures:

• stable mounting of the fuel rail at the designated mounting points,
• proper routing of lines to the injectors, without stress or twisting,
• preservation of the factory layout of accessories in the engine bay, facilitating service and diagnostics.

Benefits of Using an Original Mercedes Fuel Rail

Choosing a fuel rail dedicated to the OM642 engine in Mercedes W164, W207, and W212 allows for maintaining the fuel system's operating parameters at the level intended by the manufacturer. The most significant advantages include:

• Factory compatibility with the common rail system in the OM642 unit,
• correct fuel distribution to all injectors, promoting even cylinder operation,
• reduced risk of leaks at high-pressure line connections,
• maintenance of stable fuel pressure across a wide range of engine loads.

By preserving the original geometry and flow parameters, the rail supports the correct operation of the engine control unit and emission control systems.

Application in the "Injector Nozzles" Category and System Diagnostics

Although the product belongs to the Injector Nozzles category, in practice, it is the central component supplying the entire injector assembly in the OM642 engine. In case of engine operation problems – such as rough idling, power loss, or increased smoke – in addition to the injectors themselves, it is worth considering the condition of the fuel rail and the integrity of the high-pressure system during diagnostics.

If you want to better understand the symptoms of wear in fuel system components, the article describing diesel injector faults, their symptoms, and possible consequences of neglect will be useful. This will allow for a more accurate assessment of when replacing the fuel rail and associated components is justified.

Product Condition and Selecting the Right Component

The offered fuel rail is a used part, allowing for economical restoration of the fuel system's functionality in Mercedes cars with the OM642 engine. Before installation, a standard check of the seals and connection cleanliness is recommended, as well as verification of compatibility with the specific engine version.

If you are looking for other components in the injector nozzles category dedicated to this brand, check out the Mercedes injector nozzles available in our store to select a complete solution for your common rail system.