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 passenger applications.
Fitted to models including the Vito (W447), Sprinter (VS30), and GLC (X253) diesel variants, the OM622.951 was engineered for durability and efficiency in mixed urban and highway use. Emissions compliance is achieved through cooled exhaust gas recirculation (EGR), a diesel particulate filter (DPF), and selective catalytic reduction (SCR) with AdBlue injection, enabling Euro 6d-TEMP compliance across its production run.
One documented reliability concern involves EGR cooler leaks, which can result in coolant contamination of the intake tract and potential engine damage. This issue, referenced in Daimler Service Information Bulletin 205070/2018, is primarily observed in high-mileage commercial vehicles subjected to frequent stop-start cycles. From 2018, revised EGR coolers with improved sealing were introduced across the engine family to mitigate the risk.
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 OM622.951 delivers strong low-end torque ideal for load-carrying and towing but requires strict adherence to 15,000 km oil change intervals using MB 229.51 oil to maintain EGR and turbocharger longevity. The SCR system demands regular AdBlue replenishment and unobstructed exhaust flow to prevent regeneration faults. EGR cooler integrity should be verified on high-mileage units, especially in urban delivery applications. Post-2018 models feature updated EGR coolers per Daimler SIB 205070/2018, reducing coolant leakage risk. DPF regeneration cycles must complete fully; frequent short trips can lead to soot saturation and limp mode. Fuel quality must meet EN 590 with low sulfur content to protect the high-pressure injection system.
Oil Specs: Requires MB 229.51 specification (5W-30) (Daimler SIB 205070/2018). Compatible with ACEA C3 standards.
Emissions: Euro 6d-TEMP certification applies to all 2016–2020 models (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under ECE R85 standards. Output maintained across EU markets with EN 590 diesel (Daimler TIS Doc. A35072).
Daimler Technical Information System (TIS): Docs A35072, SIB 205070/2018
VCA Type Approval Database (VCA/EMS/5678)
European Commission Regulation (EU) 2017/1151
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.
Locate the engine identification number stamped horizontally on the left-side engine block near the exhaust manifold (Daimler TIS A35072). The 8th VIN digit indicates engine type ('6' for OM622 series). Pre-2018 models have grey EGR cooler housings; post-2018 units use black housings with revised gasket design. Critical differentiation from OM651: OM622.951 has a single VGT turbo and front-mounted timing cover, while OM651 uses a twin-turbo setup. Service parts require production date verification—EGR coolers before 07/2018 are not interchangeable with later versions due to internal redesign (Daimler SIB 205070/2018).
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.
Find answers to most commonly asked questions about MERCEDES-BENZ OM622951.
Comprehensive technical documentation and regulatory references
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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