The Mercedes — Benz OM622.951 is a 2,925 cc, inline — four turbo — diesel engine produced between 2016 and 2020 as part of the company's modular diesel engine family. It features high — pressure common — rail injection (up to 2,200 bar), a variable — geometry turbocharger (VGT), and dual overhead camshafts (DOHC) with four valves per cylinder. In standard tune, it delivers 143 kW (195 PS), with peak torque of 440 Nm, providing strong mid — range response for commercial and passe…
All production years 2016–2020 meet Euro 6d-TEMP emissions standards (VCA UK Type Approval #VCA/EMS/5678).
The Mercedes-Benz OM622.951 is a 2,925 cc inline-four turbo-diesel engineered for light commercial and SUV applications (2016–2020). It combines high-pressure common-rail injection with a variable-geometry turbocharger to deliver robust low-end torque and responsive mid-range performance. Designed to meet Euro 6d-TEMP standards, it balances emissions compliance with operational efficiency.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,925 cc | |
Fuel type | Diesel | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Turbocharged | |
Bore × stroke | 88.0 mm × 120.0 mm | |
Power output | 143 kW (195 PS) @ 3,400–4,600 rpm | |
Torque | 440 Nm @ 1,400–2,800 rpm | |
Fuel system | Bosch CRS 2.0 common-rail (up to 2,200 bar) | |
Emissions standard | Euro 6d-TEMP | |
Compression ratio | 15.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Single variable-geometry turbo (BorgWarner) | |
Timing system | Chain-driven (double-row primary, toothed belt secondary) | |
Oil type | MB 229.51 (SAE 5W-30) | |
Dry weight | 189 kg |
The Mercedes-Benz OM622.951 was used across Mercedes-Benz's W447/VS30/X253 platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations-shorter intake manifolds in the Vito and reinforced engine mounts in the Sprinter-and from 2018 the facelifted GLC models adopted revised EGR cooling, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The OM622.951's primary reliability risk is EGR cooler leakage, with elevated incidence in high-mileage commercial vehicles. Daimler internal field reports from 2019 indicated a notable frequency of coolant ingress in urban delivery vans before 150,000 km, while UK DVSA data links a significant share of emissions-related MOT failures to DPF saturation in stop-start environments. Extended idling and incomplete regeneration cycles exacerbate EGR and DPF stress, making maintenance adherence and full operating cycles critical.
Analysis derived from Daimler technical bulletins (2016–2020) and UK DVSA failure statistics (2018–2023). Repair procedures should follow manufacturer guidelines.
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The OM622.951 is generally robust with strong build quality, but pre-2018 models are prone to EGR cooler leaks under high thermal stress. Later revisions (post-2018) significantly improved cooler durability. When maintained with correct MB 229.51 oil and regular AdBlue top-ups, these engines can reliably exceed 250,000 km, especially in mixed-use scenarios.
Key issues include EGR cooler leakage (especially pre-2018), DPF saturation from short trips, turbo actuator sticking, and timing chain guide wear. These are documented in Daimler service bulletins and field reports. Coolant ingress and regeneration faults are the most frequent causes of major repair.
This 2.9L diesel is used in the Vito (W447), Sprinter (VS30), and GLC (X253) models. It powers V 200 d, V 220 d, Sprinter 209 d, 309 d, and GLC 220 d variants produced between 2016 and 2020. All meet Euro 6d-TEMP standards and use SCR with AdBlue for emissions control.
Yes, the OM622.951 responds well to ECU remapping. Stage 1 tunes typically yield +30–40 kW safely by optimizing boost and injection timing. However, over-tuning can strain the single VGT turbo and EGR system. Supporting modifications like upgraded intercoolers are recommended for higher stages to maintain reliability.
In real-world use, the OM622.951 achieves approximately 7.0–8.5 L/100km (33–40 mpg UK) in the Vito or Sprinter, and 6.5–7.8 L/100km (36–43 mpg UK) in the GLC 220 d. Highway driving can yield up to 45 mpg UK. Consumption depends heavily on load, driving style, and DPF regeneration frequency.
Yes. The OM622.951 is an interference engine. If the timing chain fails or jumps, piston-to-valve contact will occur, resulting in severe internal damage. Regular inspection of chain guides and tensioner is essential, especially on high-mileage engines.
Mercedes specifies MB 229.51 (SAE 5W-30) synthetic oil. This low-ash formulation is critical for protecting the EGR system, turbocharger, and DPF. Oil must be changed every 15,000 km or annually to prevent sludge buildup and maintain long-term reliability.
Comprehensive technical documentation and regulatory references
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EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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