Mercedes W205 C253 Engine Top Upper Cover Left N/S 300d OM654 A6540106505

Mercedes W205 C253 Engine Top Upper Cover Left N/S 300d OM654 is an original component from the Tappet and Valve Covers group, designed for 300d diesel units. It ensures organized routing of the upper engine section, protecting key components from contaminants and external environmental factors. This is a practical solution for users who want to maintain the engine bay in proper technical and visual condition.

Specifications and technical data

• SKU: A6540106505
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6540106505
• Substitutable numbers: A6540106505, A 654 010 65 05
• Location on the vehicle: Left
• Fuel type: Diesel
• Category: Rocker & Valve Covers

Purpose and function of the cover

The presented cover is dedicated to the OM654 power unit in the 300d version and is mounted on the left side of the engine bay. Its task is to provide a stable cover for the upper part of the mechanism, including the tappet and valve area, which limits the ingress of dust, moisture, and small contaminants into sensitive zones. As a result, this component supports the maintenance of proper operating conditions for the diesel engine and facilitates subsequent service maintenance.

Benefits of using an original cover

Using a factory cover in Mercedes W205 and C253 diesel models translates into a number of practical advantages:

• Precise fit to the geometry of the OM654 unit and adjacent components in the engine bay.
• Stable mounting, which minimizes the risk of unwanted vibrations and noise during engine operation.
• Better protection of the upper engine part against dirt, which helps maintain clarity during inspections and repairs.
• Consistent, organized appearance of the engine bay, in line with the factory standard of the Mercedes brand.

Technical characteristics and installation

The cover has been designed specifically for use with the diesel engine, which means it is adapted to the typical thermal conditions and loads occurring in this unit. The placement on the left side of the engine bay requires maintaining the appropriate geometry so as not to interfere with other sub-assemblies and to ensure convenient service access. The item comes from a used vehicle, which is important when selecting spare parts for maintenance repairs or restoring the completeness of engine equipment.

Application in service practice

Replacing the upper cover on the left side is recommended in situations where the existing element is mechanically damaged, deformed, or missing after previous repairs. A properly selected cover:

• helps reduce the accumulation of dirt in the area of tappets and valves,
• facilitates maintaining clarity during diagnostics and service,
• contributes to maintaining the factory standard of the power unit housing. For workshops specializing in the service of W205 and C253 models with diesel engines, this is a practical supplementary element that allows for repairs to be carried out in accordance with the manufacturer's specifications.

Expansion of engine area upgrades

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 additional covers, lids, or upper housing components, check the available parts in the Mercedes Tappet and Valve Covers category. For users interested in a broader view of the operation of Mercedes diesel units and the impact of equipment on engine performance, an article describing the characteristics and refreshing of the popular V6 CDI unit may be helpful – you can find it here: The second life of the Mercedes OM642 engine – how injectors and turbochargers restore the power of the 3.0 V6 CDI.