Mercedes W639 W906 Turbocharger Turbo Upper Cover Diesel OM651 A6510900186

Mercedes W639 W906 Turbocharger Turbo Upper Cover is a precision turbocharging system component designed for Mercedes diesel engines from the OM651 family. This used, original cover from the Turbochargers and parts category allows for a technically correct repair or restoration of the factory turbocharger configuration, maintaining proper airflow and stable mounting of accessories. It is a practical solution for workshops and users who expect proven geometry and solid construction without the need to invest in a new component.

Specifications and technical data

• SKU: A6510900186-3
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6510900186
• Substitutable numbers: A6510900186, A 651 090 01 86
• Fuel type: Diesel
• Category: Turbos & Parts

Purpose and role in the turbocharging system

The turbocharger upper cover in the OM651 diesel engine is responsible for the stable sealing of the housing and the proper guidance of the airflow within the compressor. In diesel units used in Mercedes W639 and W906 series, this component affects:

• maintaining tightness in the compressor area,
• correct positioning of connections and mounts,
• preserving the factory airflow geometry. As a result, the turbocharging system can operate under stable conditions, which promotes smooth torque development and proper operation of the diesel engine.

Benefits of using an original cover

Using an original turbocharger upper cover in a Mercedes with an OM651 diesel engine provides a number of practical assembly and operational benefits:

• Factory fit – dimensional compatibility with the turbocharger housing and adjacent accessory components is maintained.
• Stable mounting – proper mounting points minimize the risk of stress and leaks during engine operation.
• Consistency with the intake system – correct alignment of channels and ports promotes even airflow.
• Rational repair cost – a used part allows for restoring a functional turbocharging system without the need to replace the complete turbocharger.

Application in diesel engines

The cover is designed for diesel engines where the turbocharger operates under high thermal and pressure loads. In such conditions, it is particularly important to ensure:

• maintenance of proper housing stiffness,
• resistance to variable temperatures in the engine compartment,
• stable connection with other components of the turbocharging system. A well-chosen turbocharger upper cover helps reduce the risk of leaks, boost pressure drops, and unwanted vibrations, which translates into more predictable diesel engine performance.

Condition and service application

The offered turbocharger upper cover is a used component, which makes it an attractive solution for workshops specializing in servicing Mercedes W639 and W906 models, as well as for conscious users looking for parts with a proven design. This type of component is particularly useful for:

• repairs after mechanical damage to the turbocharger housing,
• restoring the completeness of the turbocharging system after previous unprofessional modifications,
• economical turbocharger regeneration while maintaining the original geometry. If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other elements from the same group, such as housings, casings, or turbocharger mounting elements, check the available parts in the Mercedes Turbochargers and parts category.

Support with selection and upgrades

When choosing a used turbocharger upper cover, it is crucial to verify compatibility with the specific engine version and accessory configuration. Proper component selection helps avoid assembly problems and ensures correct cooperation with the existing intake and exhaust system. In the context of refreshing older Mercedes models, especially those close to youngtimer status, it is worth considering a broader upgrade of the turbocharging system and engine accessories – practical tips can be found in the article The second life of a youngtimer – how used car parts rejuvenate cars from 1998–2012. For users and workshops that regularly use used components, a guide describing best practices for online purchasing, including verifying compatibility based on manufacturer markings and technical parameters, may also be helpful – detailed tips can be found in the material Safe purchase of used car parts online – a step-by-step guide.