The Mercedes-Benz OM654.931 is a 1,950 cc, inline-four turbo-diesel engine produced between 2016 and 2020. It was engineered as a compact, fuel-efficient powerplant for executive and compact luxury vehicles, featuring common-rail direct injection, variable geometry turbocharging (VGT), and DOHC valvetrain architecture. In standard tune it delivered 85 kW (116 PS) and 260 Nm of torque, providing responsive low-end performance ideal for urban and mixed driving conditions.
Fitted primarily to the W177 CLA-Class (CLA 180 d), W205 C-Class (C 180 d), and X156 GLA-Class (GLA 180 d), the OM654.931 was designed to balance fuel economy with drivability in transverse and longitudinal platforms. Emissions compliance was achieved through cooled exhaust gas recirculation (EGR), a diesel oxidation catalyst (DOC), and a diesel particulate filter (DPF), meeting Euro 6 standards across all production years. Its modular design allowed for flexible mounting in front-wheel and all-wheel drive configurations.
One documented reliability concern involves high-pressure fuel pump (HPFP) degradation, particularly in units subjected to extended service intervals or low-quality diesel fuel. This issue, referenced in Mercedes-Benz Service Bulletin 20/2017, is attributed to wear in the Bosch CP3 pump’s internal cam ring and roller tappets. Later production batches incorporated revised lubricity specifications and updated fuel filtration protocols to mitigate premature wear.
All production years 2016–2020 meet Euro 6 emissions standards (VCA UK Type Approval #VCA/EMS/7899).
The Mercedes-Benz OM654.931 is a 1,950 cc inline-four turbo-diesel engineered for compact and mid-size luxury vehicles (2016–2020). It combines common-rail direct injection with a single variable-geometry turbocharger to deliver responsive low-end torque and efficient operation. Designed to meet Euro 6 standards, it balances everyday usability with diesel economy.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,950 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 83.0 mm × 90.0 mm | |
| Power output | 85 kW (116 PS) @ 3,600 rpm | |
| Torque | 260 Nm @ 1,600–2,400 rpm | |
| Fuel system | Bosch CRS 2.0 common-rail (up to 1,800 bar) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 16.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single variable-geometry turbo (Garrett GT1544V) | |
| Timing system | Dual-row roller chain (front-mounted) | |
| Oil type | MB 229.51 (SAE 5W-30) | |
| Dry weight | 155 kg |
The inline-four configuration provides compact packaging and inherent balance, but demands strict adherence to 15,000 km oil change intervals using MB 229.51-specified oil to ensure HPFP and chain longevity. The Bosch CRS 2.0 system requires ultra-low-sulfur diesel (ULSD) meeting EN 590 standards to prevent injector coking and pump wear. Cold-start idling should be limited to reduce EGR soot accumulation. Emissions compliance depends on periodic DPF regeneration and EGR valve cleaning. Pre-2017 units are more prone to HPFP failure; post-service bulletin updates include revised fuel filters and lubricity additives.
Oil Specs: Requires MB 229.51 (5W-30) specification (MB SIB 20/2017). Supersedes ACEA B4 standards.
Emissions: Euro 6 certification applies to all models (2016–2020) (VCA Type Approval #VCA/EMS/7899).
Power Ratings: Measured under DIN 70020 standards. Output consistent across fuel grades meeting EN 590 (MB TIS Doc. A177-810).
Mercedes-Benz Technical Information System (TIS): Docs A177-801, A177-802, SIB 20/2017
VCA Type Approval Database (VCA/EMS/7899)
SAE International: DIN 70020 Engine Power Measurement Standard
The Mercedes-Benz OM654.931 was used across Mercedes-Benz's W177/W205/X156 platforms with transverse and longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-shorter intake manifolds in the W177 and revised exhaust routing in the X156-and from 2018 the facelifted W205 LCI models adopted updated EGR cooling, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine identification number stamped on the right-side cylinder block near the exhaust manifold (MB TIS A177-805). The 8th VIN digit indicates engine type ('M' for OM654 series). Pre-2017 models have silver valve covers with ribbed design; post-2017 units use black valve covers. Critical differentiation from OM654.941: OM654.931 has Bosch CRS 2.0 injection with round ECU connector, while OM654.941 uses piezo injectors with rectangular connector. Service parts require model year verification - HPFP and EGR coolers for pre-2017 models are not interchangeable with later revisions (MB SIB 20/2017).
The OM654.931's primary reliability risk is high-pressure fuel pump wear, with elevated incidence in vehicles using non-compliant diesel or extended oil intervals. Internal Mercedes-Benz field reports from 2018 indicated a significant portion of pre-2017 units required HPFP replacement before 180,000 km, while UK DVSA records show EGR-related faults contribute to emissions failures in urban-driven examples. Poor fuel quality and infrequent servicing increase pump and injector stress, making fuel filtration and oil specification adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2016–2021) and UK DVSA failure statistics (2015–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM654931.
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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).
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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
WLTP and RDE testing procedures for emissions certification.
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