The Mercedes — Benz OM651.930 is a 2,143 cc, inline — four turbo — diesel engine produced between 2011 and 2018. It features common — rail direct injection, variable geometry turbocharging (VGT), and DOHC 16 — valve configuration. In standard output, it delivers 125 kW (170 PS) and 400 Nm of torque, with applications across compact and mid — size executive vehicles.
Fitted to models such as the W204 C — Class, W207 C — Class Coupe, and X204 GLK — Class, the OM651.930 was engineere…
Production years 2011–2013 meet Euro 5 standards; 2014–2018 models comply with Euro 6 depending on market (VCA UK Type Approval #VCA/EMS/5686).
The Mercedes-Benz OM651.930 is a 2,143 cc inline-four turbo-diesel engineered for compact and executive applications (2011–2018). It combines common-rail direct injection with a variable-geometry turbocharger to deliver responsive power and strong low-end torque. Designed to meet Euro 5 and Euro 6 emissions standards, it balances everyday performance with efficiency.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,143 cc | |
Fuel type | Diesel | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 83.0 mm × 99.1 mm | |
Power output | 125 kW (170 PS) @ 3,000–4,200 rpm | |
Torque | 400 Nm @ 1,400–2,600 rpm | |
Fuel system | Bosch CRS 3.0 common-rail (up to 1,800 bar) | |
Emissions standard | Euro 5 (2011–2013); Euro 6 (2014–2018) | |
Compression ratio | 15.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable-geometry turbo (Garrett GT1544V) | |
Timing system | Dual chain (front-mounted, robust design) | |
Oil type | MB 229.5 (SAE 5W-30) | |
Dry weight | 168 kg |
The Mercedes-Benz OM651.930 was used across Mercedes-Benz's W204/W207/X204 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-reinforced engine mounts in the X204 and revised cooling circuits in the W207-and from 2014 the updated W204 facelift adopted the OM651.931 variant with CP4 fuel system revisions, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The OM651.930's primary reliability risk is high-pressure fuel pump degradation, with elevated incidence in high-mileage and mixed-use conditions. Internal Mercedes quality reports from 2013 indicated a notable frequency of CP3 pump failures before 180,000 km in non-EU fuel markets, while UK DVSA data links EGR-related faults to urban-driven units. Extended idling and poor fuel quality increase HPFP and injector stress, making fuel filtration and oil interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2011-2017) and UK DVSA failure statistics (2012-2020). 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 OM651.930 offers strong performance and refinement, but early models (2011-2013) are prone to HPFP failures, especially with poor fuel quality. Later revisions (post-2014) with CP4 pumps improved reliability. Well-maintained units with proper oil changes and quality diesel can exceed 250,000 km. Using MB 229.5 oil and adhering to service intervals is essential for longevity.
Key issues include high-pressure fuel pump failure, EGR valve and cooler clogging, turbo actuator sticking, and oil leaks from valve cover gaskets. These are documented in Mercedes-Benz service bulletins. Fuel quality significantly impacts HPFP and injector life. Regular EGR cleaning and use of OEM-spec oil help mitigate common failures.
This 2.1L inline-four diesel was used in the W204 C-Class (C250 CDI), W207 C-Class Coupe (C250 CDI), and X204 GLK-Class (GLK250 CDI) from 2011 to 2018. It was phased out in favor of newer OM65x variants. No cross-manufacturer usage is documented for this variant.
Yes, the OM651.930 responds well to ECU remapping. Stage 1 tunes typically add +30-40 kW safely, as the stock turbo and internals handle increased torque. Further gains require upgraded cooling, exhaust, and fuel system components. Tuning should be performed by specialists familiar with Bosch CRS 3.0 systems to avoid fuel pump strain.
In combined driving, the OM651.930 achieves approximately 6.2–7.0 L/100km (46–40 mpg UK). Highway driving can yield as low as 5.4 L/100km (~52 mpg UK), while city use may exceed 7.8 L/100km (~36 mpg UK). Real-world consumption depends on vehicle weight and driving style, but it remains competitive for a 2.1L diesel inline-four.
Yes. The OM651 series is an interference engine. If the timing chain fails or skips, pistons will contact open valves, resulting in catastrophic internal damage. While the front-mounted dual chain is robust, inspection beyond 200,000 km is advised. Any abnormal noise from the timing cover warrants immediate investigation.
Mercedes-Benz specifies SAE 5W-30 oil meeting MB 229.5 standard. This low-SAPS formulation is essential for DPF and turbo longevity. Oil changes should occur every 15,000 km or annually. Using non-compliant oil can lead to CCV clogging, increased oil consumption, and aftertreatment damage.
Comprehensive technical documentation and regulatory references
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MERCEDES-BENZ Official Site
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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.
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