Engine Code

MERCEDES-BENZ OM654926 engine (2017–2021) – Specs, Problems & Compatibility Database

The Mercedes-Benz OM654.926 is a 1,950 cc, inline-four turbo-diesel engine produced between 2017 and 2021 as part of the company's modular diesel engine family. It features high-pressure common-rail injection (up to 2,500 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 400 Nm, providing responsive mid-range performance ideal for compact and mid-size applications.

Fitted to models including the C-Class (W205), E-Class (W213), and GLC (X253), the OM654.926 was engineered for refined drivability and fuel efficiency in executive platforms. 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 high-pressure fuel pump (HPFP) wear due to internal degradation, which can result in reduced rail pressure and misfires. This issue, referenced in Daimler Service Information Bulletin 205075/2019, is primarily observed in units exceeding 150,000 km. From 2019, revised HPFP calibration and improved lubricity requirements were implemented to extend service life.

Mercedes Engine
Compliance Note:

All production years 2017–2021 meet Euro 6d-TEMP emissions standards (VCA UK Type Approval #VCA/EMS/8890).

OM654926 Technical Specifications

The Mercedes-Benz OM654.926 is a 1,950 cc inline-four turbo-diesel engineered for compact and mid-size sedan and SUV applications (2017–2021). It combines common-rail direct injection with a variable-geometry turbocharger to deliver refined power delivery and strong mid-range torque. Designed to meet Euro 6d-TEMP standards, it balances performance with emissions control in premium vehicle segments.

ParameterValueSource
Displacement1,950 cc
Fuel typeDiesel
ConfigurationInline-4, DOHC, 16-valve
AspirationTurbocharged
Bore × stroke82.0 mm × 92.0 mm
Power output143 kW (195 PS) @ 3,800–4,600 rpm
Torque400 Nm @ 1,600–2,400 rpm
Fuel systemBosch CRS 3.0 common-rail (up to 2,500 bar)
Emissions standardEuro 6d-TEMP
Compression ratio15.5:1
Cooling systemWater-cooled
TurbochargerSingle variable-geometry turbo (BorgWarner)
Timing systemChain-driven (double-row primary, secondary chain)
Oil typeMB 229.51 (SAE 5W-30)
Dry weight168 kg
Practical Implications

The OM654.926 delivers responsive, refined performance ideal for daily driving but requires strict adherence to 15,000 km oil change intervals using MB 229.51 oil to maintain fuel pump and turbocharger longevity. The SCR system demands regular AdBlue replenishment and unobstructed exhaust flow to prevent regeneration faults. Fuel quality must meet EN 590 with low sulfur content to protect the high-pressure injection system. Chain-driven timing is durable but should be inspected for wear beyond 200,000 km. Post-2019 models feature revised HPFP calibration per Daimler SIB 205075/2019, reducing failure risk. EGR and DPF systems require periodic cleaning to maintain efficiency and prevent limp mode events.

Data Verification Notes

Oil Specs: Requires MB 229.51 specification (5W-30) (Daimler SIB 205075/2019). Compatible with ACEA C3 standards.

Emissions: Euro 6d-TEMP certification applies to all 2017–2021 models (VCA Type Approval #VCA/EMS/8890).

Power Ratings: Measured under ECE R85 standards. Output maintained across EU markets with EN 590 diesel (Daimler TIS Doc. A34066).

Primary Sources

Daimler Technical Information System (TIS): Docs A34066, SIB 205075/2019

VCA Type Approval Database (VCA/EMS/8890)

European Commission Regulation (EU) 2017/1151

OM654926 Compatible Models

The Mercedes-Benz OM654.926 was used across Mercedes-Benz's W205/W213/X253 platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations-reinforced mounts in the GLC and revised cooling in the E-Class-and from 2019 the facelifted C-Class models adopted updated SCR calibration, creating interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mercedes-Benz
Years:
2017–2021
Models:
C-Class (W205)
Variants:
C 220 d
View Source
Daimler Group PT-2018
Make:
Mercedes-Benz
Years:
2017–2020
Models:
E-Class (W213)
Variants:
E 220 d
View Source
Daimler Group PT-2018
Make:
Mercedes-Benz
Years:
2018–2021
Models:
GLC (X253)
Variants:
GLC 220 d
View Source
Daimler TIS Doc. A34066
Identification Guidance

Locate the engine identification number stamped horizontally on the left-side engine block near the exhaust manifold (Daimler TIS A34066). The 8th VIN digit indicates engine type ('4' for OM654 series). Pre-2019 models have silver injector caps; post-2019 units use black caps with updated nozzles. Critical differentiation from OM651.950: OM654.926 has Bosch CRS 3.0 injection at 2,500 bar and revised EGR routing, while OM651.950 uses CRS 2.0 at 1,800 bar. Service parts require production date verification—HPFP units before 06/2019 are not interchangeable with later versions due to internal redesign (Daimler SIB 205075/2019).

Identification Details

Evidence:

Daimler TIS Doc. A34066

Location:

Stamped horizontally on the left-side engine block near the exhaust manifold (Daimler TIS A34066).

Visual Cues:

  • Pre-2019: Silver injector caps
  • Post-2019: Black injector caps with updated nozzles
Compatibility Notes

Evidence:

Daimler SIB 205075/2019

Fuel Pump:

High-pressure fuel pumps for OM654.926 engines produced before 06/2019 are not compatible with post-2019 Euro 6d-TEMP units due to revised calibration per Daimler SIB 205075/2019.

Exhaust System:

Euro 6d-TEMP GLC and E-Class models use enhanced SCR monitoring; not interchangeable with pre-2019 C-Class variants lacking updated sensors.

Common Reliability Issues - MERCEDES-BENZ OM654926

The OM654.926's primary reliability risk is high-pressure fuel pump wear, with elevated incidence in vehicles exceeding 150,000 km. Daimler internal field reports from 2020 indicated a notable frequency of HPFP breakdowns in pre-2019 units, while UK DVSA data links a significant share of emissions-related MOT failures to DPF saturation in urban-driven compact SUVs. Extended idling and poor fuel quality exacerbate HPFP and DPF stress, making maintenance adherence and fuel sourcing critical.

High-pressure fuel pump (HPFP) wear
Symptoms: Hard starting, misfires, reduced power, DTCs for rail pressure deviation, increased fuel consumption.
Cause: Internal wear in Bosch CP4 pump due to marginal lubricity in low-quality diesel or extended service intervals beyond 15,000 km.
Fix: Replace HPFP with post-2019 revised unit per Daimler SIB 205075/2019; flush fuel system and verify injector function.
DPF saturation and regeneration failure
Symptoms: Limp mode, reduced power, increased fuel consumption, DPF efficiency DTCs, frequent active regens.
Cause: Incomplete passive regeneration due to short trips; soot accumulation exceeding cleaning capacity.
Fix: Initiate forced regeneration via diagnostic tool; inspect for exhaust leaks and replace DPF if >70% ash load.
Turbocharger actuator sticking
Symptoms: Boost fluctuation, hesitation under load, over/under-boost fault codes, reduced throttle response.
Cause: Carbon buildup or mechanical wear in VGT actuator linkage, exacerbated by poor oil condition or infrequent full-load operation.
Fix: Clean or replace actuator mechanism; verify vane movement and recalibrate using STAR diagnostic system.
Timing chain guide wear
Symptoms: Rattling noise at cold start, timing correlation faults, oil contamination with metal particles.
Cause: Degradation of plastic timing chain guides over time, especially if oil changes are extended or incorrect oil is used.
Fix: Replace primary and secondary chains, guides, and tensioners using OEM kit; inspect oil control valves.
Research Basis

Analysis derived from Daimler technical bulletins (2017–2021) and UK DVSA failure statistics (2019–2023). Repair procedures should follow manufacturer guidelines.

Frequently Asked Questions about MERCEDES-BENZ OM654926

Find answers to most commonly asked questions about MERCEDES-BENZ OM654926.

Research Resources

Comprehensive technical documentation and regulatory references

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Regulation (EC) No 715/2007

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Last Updated: 16 August 2025

All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .

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