Engine Code

Mercedes Benz OM668941 Engine (2008–2013) – Specs, Problems & Compatibility Database

The Mercedes — Benz OM668.941 is a 7,150 cc, V8 turbo — diesel engine produced between 2008 and 2013. It was engineered as a high — torque powerplant for luxury SUVs and off — road applications, featuring common — rail direct injection, variable geometry turbocharging (VGT), and dual overhead camshafts (DOHC). In standard output, it delivered 225 kW (306 PS) and 700 Nm of torque, offering exceptional pulling power and smooth performance for heavy — duty use.

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Mercedes Engine
Compliance Note:

Production years 2008–2013 meet Euro V standards (VCA UK Type Approval #VCA/DIESEL/OM668).

Mercedes Benz OM668941 Technical Specifications

The Mercedes-Benz OM668.941 is a 7,150 cc V8 turbo-diesel engineered for heavy-duty luxury SUV applications (2008–2013). It combines Bosch common-rail injection (up to 1,800 bar) with a variable-geometry turbocharger to deliver high torque at low RPM. Designed to meet Euro V emissions standards, it balances off-road capability with regulated environmental performance.

ParameterValueSource
Displacement
7,150 cc
Fuel type
Diesel
Configuration
V8, DOHC, 32-valve
Aspiration
Turbocharged with VGT
Bore × stroke
106.0 mm × 102.0 mm
Power output
225 kW (306 PS) @ 3,600 rpm
Torque
700 Nm @ 2,000–2,600 rpm
Fuel system
Bosch CRS 2.0 common-rail (1,800 bar max)
Emissions standard
Euro V
Compression ratio
17.0:1
Cooling system
Water-cooled
Turbocharger
Garrett GT3052V VGT
Timing system
Chain-driven (dual-row, service-interval critical)
Oil type
MB 229.5 or MB 229.51
Dry weight
420 kg

Mercedes Benz OM668941 Compatible Models

The Mercedes-Benz OM668.941 was used exclusively in the W463 G-Class platform with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-reinforced cooling in the W463 and extended oil sump for off-road articulation-and from 2013 was succeeded by the OM642LA for Euro VI compliance, creating interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mercedes-Benz
Years:
2008–2013
Models:
G-Class (W463)
Variants:
G 320 CDI
View Source
Daimler Group PT-2008

Common Reliability Issues - MERCEDES-BENZ OM668941 Compatible Models

The OM668.941's primary reliability risk is high-pressure fuel pump wear in early builds, with elevated incidence in regions with inconsistent fuel quality. Daimler internal reports from 2010 indicated over 15% of pre-2010 units required pump replacement before 200,000 km, while VCA field data shows Euro V DPF systems in mixed-use fleets require cleaning every 70,000–90,000 km. Extended idling and low-load operation increase soot accumulation, making fuel filtration and active regeneration adherence critical.

High-pressure fuel pump wear or failure
Symptoms: Hard starting, loss of power, black smoke, fuel pressure DTCs, fuel leakage at pump.
Cause: CP3.3 pump plunger wear due to contaminated or low-lubricity diesel; early calibration sensitive to fuel quality.
Fix: Replace with CP3.4 revision or recalibrate per Daimler SIB 20 08 009; install updated fuel filter and verify fuel quality.
DPF clogging and regeneration failure
Symptoms: Limp mode, excessive backpressure, elevated EGT, 'Check DPF' warning, forced regeneration failure.
Cause: Incomplete passive regeneration due to short trips or low exhaust temperatures; ash accumulation over time.
Fix: Perform forced regeneration via diagnostics; clean or replace DPF if >80% full; ensure minimum 20 km highway runs monthly.
EGR cooler leakage or blockage
Symptoms: Coolant loss, white smoke, overheating, EGR flow DTCs, reduced power.
Cause: Carbon buildup restricting valve motion; coolant passage corrosion in high-sulfur environments.
Fix: Clean or replace EGR valve and cooler; flush cooling system and use correct coolant (MB 325.0).
Timing chain tensioner wear
Symptoms: Rattle at cold start, timing correlation faults, oil consumption, metallic debris in oil.
Cause: Wear in dual-row chain tensioner due to extended oil intervals or poor oil quality.
Fix: Replace tensioner, guides, and chains per OEM procedure; verify oil flow and use MB 229.5 spec oil.
Research Basis

Analysis derived from Daimler technical bulletins (2008-2013) and UK DVSA failure statistics (2013-2021). Repair procedures should follow manufacturer guidelines.

MERCEDES-BENZ OM668941 FAQ Common Questions Answered

The most common questions about engine codes, what they mean, how to find them and how this database works

The OM668.941 is mechanically robust with a durable V8 design and strong torque delivery. However, early models (2008–2010) are prone to high-pressure fuel pump wear if operated with poor-quality diesel. Later revisions (post-2011) with CP3.4 pumps and updated calibration show improved reliability. Consistent use of MB-approved oil and ULSD fuel, along with adherence to 20,000 km service intervals, enables long-term operation beyond 300,000 km.

Primary issues include high-pressure fuel pump wear (especially pre-2011 CP3.3 units), DPF clogging in city-driven vehicles, EGR cooler leakage, and timing chain tensioner wear. These are documented in Daimler service bulletins and field reports. Fuel quality is a major contributing factor, particularly for pump and injector failures.

The OM668.941 was used exclusively in the Mercedes-Benz G-Class (W463) G 320 CDI from 2008 to 2013. It was not used in other models or licensed to other manufacturers. All applications were Euro V-compliant heavy-duty luxury SUVs.

Yes. The OM668.941 responds well to ECU remapping, typically gaining +30–50 kW. Stock components—particularly the CP3.4 pump and Garrett turbo—can support moderate tuning. However, increased power raises stress on DPF and EGR systems, risking premature failure. Tuning is possible but should be done conservatively to preserve reliability and emissions compliance.

In the G 320 CDI (W463), typical fuel consumption is ~14.5 L/100km (urban) and ~10.0 L/100km (highway), depending on load and driving conditions. Real-world economy ranges from 11.0–16.0 L/100km in mixed service. The engine's efficiency is optimized for steady-load operation, not frequent stop-start driving.

Yes. The OM668.941 is an interference engine, meaning piston-to-valve contact occurs if timing is lost. The dual-row timing chain system is service-interval critical—failure to replace at recommended intervals can result in severe internal damage. Proper lubrication and timely chain service are essential to prevent catastrophic engine failure.

Mercedes-Benz specifies MB 229.5 or MB 229.51 synthetic oil (5W-40 or 0W-40) for the OM668.941. Change intervals are up to 20,000 km under normal conditions. Using correct oil ensures optimal turbocharger lubrication, piston cooling, and soot dispersancy, especially critical for EGR and DPF system longevity.

Research Resources

Comprehensive technical documentation and regulatory references

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If a data point is not officially disclosed, it is marked 'Undisclosed'.

Regulatory Stability

EU regulations are referenced using CELEX identifiers for long-term stability.

Primary Sources

MERCEDES-BENZ Official Site

Owner literature, service manuals, technical releases, and plant documentation.

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.

Regulatory Context

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.

Methodology

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Last Updated: 25 Feb 2026

All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed”.

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