Valve Mercedes W204 Diesel Engine OM642 Fuel Pressure Regulator A6420740284

The Mercedes W204 Diesel Engine OM642 Fuel Pressure Regulator is an original fuel system component designed for diesel engines, engineered for precise control of engine operating parameters. Thanks to its factory design, the regulator works stably with the injection system, which translates to smooth engine operation and proper response to load. This is a solution for users who expect consistency with factory specifications and want to maintain the correct operating characteristics of the OM642 engine.

Specifications and technical data

• SKU: A6420740284
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6420740284
• Substitutable numbers: A6420740284, A 642 074 02 84
• Fuel type: Diesel
• Category: Other Air & Fuel Delivery

Purpose and Role in the Fuel System

The fuel pressure regulator in a diesel engine is responsible for maintaining the correct pressure in the fuel rail, ensuring that injectors receive fuel under strictly defined conditions. In diesel engines like the OM642, stable pressure is crucial for:

• correct fuel delivery across the entire RPM range,
• maintaining engine smoothness at low and high loads,
• reducing smoke and unwanted vibrations,
• preserving factory performance parameters and fuel consumption.

A properly selected regulator helps avoid starting problems, power drops, or rough idling, which is important for both daily driving and long-distance highway journeys.

Compatibility with OM642 Diesel Engine

The presented component is designed to work with the OM642 Diesel engine, used in Mercedes mid-size models, including the W204 series. The regulator's design is adapted to the operating pressure characteristics of this engine, ensuring the injection system maintains proper responsiveness to changes in load and fuel demand.

In practice, this means that after correct installation, the engine control unit receives stable operating conditions, which facilitates the diagnosis of any other faults and maintains consistency with the injection maps stored in the ECU software.

Product Features and Benefits of Use

The fuel pressure regulator offered here is an original Mercedes part and is classified as a used part. For many users and workshops, this represents a favorable compromise between repair cost and maintaining the original fuel system design. Compared to aftermarket parts of unknown origin, an original regulator ensures:

• operation parameters consistent with the vehicle manufacturer's design,
• better predictability of engine behavior in various operating conditions,
• easier integration with the existing fuel and electrical systems,
• reduced risk of problems arising from differences in operating characteristics.

For vehicles used intensively, including fleet applications, installing an original regulator is often the preferred service solution, allowing for the restoration of correct engine operation without altering the control unit software.

Professional Service Application

The fuel pressure regulator for the Mercedes W204 diesel engine is a component whose replacement requires adherence to service procedures, including proper system bleeding and leak testing. For this reason, the product is often chosen by workshops specializing in diesel engine service, where repair result repeatability and the possibility of subsequent computer diagnostics are important.

For vehicles that have undergone modifications or have high mileage, using an original regulator makes it easier to assess the condition of other injection system components, as it eliminates the variable of uncertain aftermarket part quality.

Related Categories and Technical Materials

If, during the service of your Mercedes' fuel system, you also need other components related to this group of parts, such as additional mounts, connectors, or accessory elements, check the available parts in the Other Mercedes category.

To compare solutions used in different vehicle brands and segments, including sports versions with advanced powertrain systems, a material discussing the design differences in high-performance engines may be helpful – more information can be found in the article Audi RS vs. Other Models – What Lies Under the Hood and Chassis?.

If you are interested in a broader perspective on selecting used market parts and want to better understand when it is worth opting for original used parts, our guide will be useful: Best Used Car Parts – A Guide to the Most Frequently Chosen Original Parts.