Mercedes W164 W204 W211 OM642 Right Fuel Injector Pressure Rail Line A6420702595

The Mercedes W164 W204 W211 OM642 Fuel Rail is an original fuel system component designed for OM642 diesel engines in select Mercedes models of the W164, W204, and W211 class. The fuel rail is responsible for the stable distribution of fuel to the injectors, which is crucial for the smooth operation of the engine and the proper functioning of the common rail system.

Specifications and technical data

• SKU: A6420702595
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420702595
• Substitutable numbers: A6420702595, A 642 070 25 95
• Location on the vehicle: Right
• Category: Fuel Injectors

Purpose and Function of the OM642 Fuel Rail

The fuel rail in the OM642 engine acts as a central high-pressure manifold from which individual injectors are supplied. A properly selected rail ensures:

• stable fuel pressure across the entire engine load range,
• uniform supply to all cylinders, which reduces vibrations and uneven engine operation,
• compatibility with the factory-fitted injection system components in Mercedes vehicles with the OM642 engine.

Selecting the correct rail is particularly important for modern diesel engines, where pressure and flow tolerances are very narrow, and an incorrectly chosen component can lead to starting problems, power loss, or engine control unit errors.

Construction and Vehicle Placement

The presented fuel rail for Mercedes OM642 is designed for installation on the right side of the engine, according to the manufacturer's original design. Correct placement on the vehicle is important for:

• proper routing of high-pressure lines to the injectors,
• unobstructed installation relative to engine components (manifolds, lines, wiring harnesses),
• maintaining the original fuel system geometry, which facilitates diagnostics and servicing.

By preserving the original geometry and mounting points, installing the rail on the right side follows the service procedures for the OM642 engine, without the need for installation modifications.

Category: Injector Nozzles and the Rail's Role in the System

This product belongs to the Injector Nozzles category, which includes components directly related to the precise delivery of fuel into the combustion chamber. Although the fuel rail is not the nozzle itself, it is a key component of the injector supply line, influencing:

• stable injector operation under varying loads,
• maintaining the correct operating pressure throughout the common rail system,
• reducing the risk of cavitation and pressure fluctuations that can accelerate injector wear.

Replacing the fuel rail is often one step in a comprehensive injection system repair, especially when problems with fuel pressure, control unit errors, or high-pressure line leaks occur.

Item Condition and Application in Service Practice

The offered fuel rail is a used part, making it an attractive solution for repairing vehicles with OM642 engines where cost-effective servicing while maintaining compliance with factory specifications is important. In workshop practice, such a component is particularly useful in situations where:

• a quick replacement of a damaged rail is necessary without long waiting times for a new part,
• a heavily used car is being repaired, where reliability and originality are key,
• diagnostic work on the injection system is being carried out and a functional rail is needed for fault verification.

Selecting the correct component for a specific W164, W204, or W211 model with an OM642 engine helps reduce compatibility issues and speeds up the repair process.

Technical Support, Diagnostics, and Additional Materials

When replacing the fuel rail, it is advisable to check the overall condition of the injection system, including the injectors, high-pressure lines, and the high-pressure pump. For users and workshops, material describing common problems with diesel engine injection systems may be useful – the article Diesel Injector Failures – How to Recognize Them and What Neglecting Them Entails thoroughly discusses these, presenting symptoms, consequences, and basic diagnostic methods.

If you are modernizing or restoring an older Mercedes from years similar to W164, W204, or W211, you will find inspiring information on using used components in the guide Second Life for a Youngtimer – How Used Car Parts Revitalize Cars from 1998–2012, which describes practical scenarios for refreshing premium class vehicles.

Other Mercedes Injector Nozzles

If, during fuel system repairs, you also need other Mercedes injector nozzles tailored to specific models and engine versions, check out our dedicated offer: Mercedes injector nozzles. This will allow you to easily assemble a complete set of injection system components within a single brand and category.