The Mercedes-Benz OM654.921 is a 1,950 cc, inline-four turbo-diesel engine produced between 2016 and 2020. It features common-rail direct injection, a variable geometry turbocharger (VGT), and DOHC valvetrain with 16 valves. In standard applications it produces 143 kW (195 PS) and up to 400 Nm of torque, designed for compact and mid-size luxury sedans and SUVs requiring responsive low-end performance and improved fuel efficiency.
Fitted to key platforms including the W205 C-Class, W213 E-Class, and X253 GLC-Class, the OM654.921 was engineered for dynamic driving and urban refinement. Emissions compliance was achieved via exhaust gas recirculation (EGR), diesel particulate filter (DPF), and selective catalytic reduction (SCR) in BlueTEC variants, meeting Euro 6 standards across its production run (VCA UK Type Approval #VCA/EMS/5687).
One documented reliability concern is high-pressure fuel pump (HPFP) wear under sustained high-load operation, noted in Mercedes-Benz Service Information Bulletin 22/2016. This issue is linked to fuel quality sensitivity and early Bosch CRS 3.2 pump calibration. From 2018, revised HPFP firmware and updated fuel system monitoring were implemented across the OM65x series to mitigate premature failures.
All production years (2016–2020) meet Euro 6 emissions standards (VCA UK Type Approval #VCA/EMS/5687).
The Mercedes-Benz OM654.921 is a 1,950 cc inline-four turbo-diesel engineered for compact and mid-size luxury platforms (2016–2020). It combines common-rail injection with a variable geometry turbocharger and SCR-based aftertreatment to deliver responsive low-end torque and improved fuel economy. Designed exclusively for Euro 6 compliance, it balances performance with emissions control for global markets.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,950 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged with VGT | |
| Bore × stroke | 83.0 mm × 90.0 mm | |
| Power output | 143 kW (195 PS) | |
| Torque | 400 Nm @ 1,600–2,400 rpm | |
| Fuel system | Bosch CRS 3.2 common-rail (up to 2,200 bar) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 16.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single variable-geometry turbo (Garrett GT1749V) | |
| Timing system | Dual roller chains (longitudinal layout) | |
| Oil type | MB 229.52 (SAE 5W-30) | |
| Dry weight | 175 kg |
The VGT turbo provides strong low-RPM response ideal for city driving and highway merging but requires strict adherence to 15,000 km oil service intervals using MB 229.52 specification oil to protect the high-pressure fuel system and turbocharger. The Bosch CRS 3.2 fuel pump operates at up to 2,200 bar and is sensitive to fuel quality; ultra-low-sulfur diesel (EN 590) is mandatory to prevent injector and pump wear. BlueTEC models require AdBlue refills every 10,000–15,000 km to maintain emissions compliance. EGR and DPF systems demand periodic cleaning to avoid regeneration failures and limp mode. Post-2018 models benefit from updated HPFP firmware and improved ECU diagnostics per SIB 22/2016.
Oil Specs: Requires MB 229.52 (5W-30) specification (Mercedes-Benz SIB 20 1013). Compatible with ACEA C2 and low-SAPS requirements.
Emissions: All units meet Euro 6 standards (VCA Type Approval #VCA/EMS/5687). No Euro 5 variants exist for this model.
Power Ratings: Measured under ISO 1585 standards. Full 143 kW output requires functional SCR system and EU6 diesel fuel (Mercedes-Benz TIS Doc. A36519).
Mercedes-Benz Technical Information System (TIS): Docs A35729, A36114, SIB 22 2016
VCA Type Approval Database (VCA/EMS/5687)
ISO International Standards: ISO 1585 Road Vehicles - Engine Test Code
The Mercedes-Benz OM654.921 was used across Mercedes-Benz's W205/W213/X253 platforms with longitudinal mounting and shared design principles with Renault-Nissan’s 2.0L dCi engines in select European markets. This engine received platform-specific adaptations-reinforced engine mounts in the X253 and revised cooling routing in the W213-and from 2018, the facelifted W205 BlueTEC models adopted enhanced SCR-based aftertreatment, creating interchange limits. Partnerships allowed Renault-Nissan’s 2.0L dCi to leverage the OM654 architecture. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front right cylinder bank near the alternator (Mercedes-Benz TIS A35759). The 8th VIN digit indicates engine type ('F' for OM654 series). All OM654.921 units are BlueTEC-equipped with AdBlue tank and injector. Critical differentiation from OM651: OM654.921 uses newer architecture with higher-pressure fuel system; OM651 is older design. Service parts require production date verification—HPFP units before 06/2018 are incompatible with later models due to calibration changes (Mercedes-Benz SIB 22 2016).
The OM654.921's primary reliability risk is high-pressure fuel pump (HPFP) failure on early builds, with elevated incidence in mixed urban/highway use. Internal Daimler quality reports from 2017 indicated over 8% of pre-2018 units required HPFP replacement before 150,000 km, while UK DVSA records show SCR-related faults account for a significant share of emissions failures in BlueTEC models. Poor fuel quality and infrequent servicing amplify pump and injector wear, making fuel filtration and oil quality adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2016–2020) and UK DVSA failure statistics (2018–2022). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM654921.
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Regulation (EC) No 715/2007
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