The Mercedes — Benz OM642.868 is a 3,009 cc, V6 turbo — diesel engine produced between 2009 and 2013. It features common rail direct injection, variable geometry turbocharging (VGT), and DOHC valvetrain with 24 valves. In high — output form, it delivers 200 kW (272 PS) and 600 Nm of torque, providing strong mid — range performance ideal for luxury and towing applications.
Fitted to the W221 S — Class (S350 CDI), W164 ML — Class (ML350 CDI), and V251 Viano (Viano 3.0 CDI BlueEFFIC…
All production years 2009–2013 meet Euro 5 standards . No Euro 6 variant of the OM642.868 was produced.
The Mercedes-Benz OM642.868 is a 3,009 cc V6 turbo-diesel engineered for premium and utility platforms (2009–2013). It combines common-rail direct injection with a single variable-geometry turbocharger to deliver responsive mid-range torque and smooth power delivery. Designed exclusively to meet Euro 5 standards, it balances high output with regulated emissions compliance via SCR/AdBlue technology.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,009 cc | |
Fuel type | Diesel | |
Configuration | 90° V6, DOHC, 24-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 88.0 mm × 82.1 mm | |
Power output | 200 kW (272 PS) @ 3,600 rpm | |
Torque | 600 Nm @ 1,600–2,400 rpm | |
Fuel system | Bosch CRS 2.0 common-rail (up to 1,800 bar) | |
Emissions standard | Euro 5 | |
Compression ratio | 16.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable-geometry turbo (Garrett GT1752V) | |
Timing system | Dual chain (front-mounted, robust design) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 198 kg |
The Mercedes-Benz OM642.868 was used across Mercedes-Benz's W221/W164/V251 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific tuning variations-smooth idle control in the W221 and revised transmission mapping in the W164-and from 2011 incorporated HPFP durability updates per service bulletin, creating minor service part distinctions. All adaptations are documented in OEM technical bulletins.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The OM642.868 is a robust V6 diesel when properly maintained. Early models (2009-2010) are prone to HPFP failure, but post-2011 revisions significantly improved reliability. Regular oil changes with MB 229.51 oil and use of clean diesel fuel are essential. Well-serviced engines can exceed 300,000 km, though vigilance for fuel system and EGR issues is recommended.
The most documented issues are high-pressure fuel pump failure (especially pre-2011), turbo actuator sticking, EGR cooler leaks, and external oil leaks from valve cover gaskets. These are supported by Mercedes-Benz service bulletins and field reports. Fuel contamination and poor maintenance accelerate these failures.
The OM642.868 was used in the W221 S-Class (S350 CDI, 2009-2013), W164 ML-Class (ML350 CDI, 2009-2011), and V251 Viano (Viano 3.0 CDI BlueEFFICIENCY, 2009-2013). It was not used in coupes or commercial models. No licensed applications in other brands exist for this engine variant.
Yes, but with caution. ECU remaps can increase output to ~230 kW (313 PS), but place additional stress on the factory HPFP and turbo. Supporting modifications—upgraded fuel filter, enhanced cooling, and high-flow exhaust—are strongly advised. Over-tuning without hardware upgrades risks premature pump or injector failure.
In combined driving, the OM642.868 achieves approximately 8.0–9.0 L/100km (31–35 mpg UK). Highway efficiency improves to ~7.0 L/100km (40 mpg UK), while city driving may reach 11.0 L/100km (26 mpg UK). Real-world consumption depends on vehicle weight and driving style, but it is competitive for a V6 diesel luxury SUV or MPV.
Yes. The OM642.868 is an interference engine. If the timing chain fails or jumps, piston-to-valve contact will occur, resulting in severe internal engine damage. However, the dual front-mounted chain system is robust and rarely fails when maintenance is up to date.
The engine requires MB 229.51 specification oil, typically SAE 5W-30. This low-ash, high-detergent formulation is critical for protecting the HPFP and turbocharger. Oil must be changed every 15,000 km or 12 months. Use of non-compliant oils increases wear and voids component longevity.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.