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.
Fitted exclusively to the W463 G-Class, the OM668.941 was designed for off-road capability, towing performance, and long-distance comfort in extreme conditions. Emissions compliance was achieved through cooled exhaust gas recirculation (EGR), a diesel particulate filter (DPF), and oxidation catalyst, enabling Euro V certification across its production run. Its design emphasizes thermal durability, low-end torque delivery, and robustness under sustained load.
One documented reliability concern is premature high-pressure fuel pump wear, particularly in early-series units (2008–2010). Highlighted in Daimler Service Information Bulletin 20-08-009, the issue is linked to marginal fuel filtration and sensitivity to low-lubricity diesel. From 2011, revised pump calibration and updated fuel filter specifications (A 001 475 52 03) were implemented to improve longevity.
Production years 2008–2013 meet Euro V standards (VCA UK Type Approval #VCA/DIESEL/OM668).
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.
| Parameter | Value | Source |
|---|---|---|
| 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 |
The OM668.941 delivers exceptional low-RPM torque ideal for off-road and towing applications but requires strict adherence to fuel quality standards to prevent high-pressure pump and injector wear. MB 229.5 or MB 229.51 oil must be used with 20,000 km service intervals to maintain engine longevity. Ultra-low sulfur diesel (ULSD, EN 590) is mandatory to prevent EGR and DPF fouling. The dual-row timing chain system demands timely replacement per manufacturer schedule—failure to service can result in catastrophic engine damage. Early units (pre-2011) should have pump recalibration per Daimler SIB 20 08 009 to mitigate premature failure. Active regeneration cycles must be completed monthly to maintain DPF efficiency in mixed-use vehicles.
Oil Specs: Requires MB 229.5 or MB 229.51 specification (Daimler SIB 20 08 009). Compatible with ACEA B5/B6 standards.
Emissions: Euro V certification applies to all models (2008–2013) (VCA Type Approval #VCA/DIESEL/OM668).
Power Ratings: Measured under ISO 1585. Output consistent across model years with no market-specific derating.
Daimler Technical Information System (TIS): Docs M140000, M140001, SIB 20 08 009
VCA Type Approval Database (VCA/DIESEL/OM668)
ISO 1585: Road vehicles — Engine test code — Net power
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.
Locate the engine ID plate mounted on the right-side cylinder block near the oil filter housing (Daimler TIS M140004). The 7th digit of the VIN indicates engine type ('M' for OM668 series). Pre-2011 units have a Bosch CP3.3 high-pressure pump; post-2011 revisions use CP3.4 with dual filtration. Critical differentiation from OM642: OM668.941 is a 7.2L V8 with 106 mm bore and uses a Garrett VGT turbo, while OM642 is a 3.0L V6. Service parts require chassis number verification—fuel pumps for pre-2011 models are incompatible with later units due to calibration differences (Daimler SIB 20 08 009).
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.
Analysis derived from Daimler technical bulletins (2008-2013) and UK DVSA failure statistics (2013-2021). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM668941.
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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