The Mercedes-Benz OM612.961 is a 2,694 cc, inline-five, turbocharged diesel engine produced between 1995 and 1998. It features indirect injection via a pre-chamber design, SOHC valvetrain, and durable cast-iron construction for long service life. In standard configuration it delivered 95 kW (129 PS) and 300 Nm of torque, providing strong low-end pull ideal for urban and highway driving.
Fitted primarily to the W124 270D and W210 E270 Diesel models, the OM612.961 was engineered for drivers seeking a balance of efficiency, reliability, and responsive performance. Emissions compliance was achieved through exhaust gas recirculation (EGR) and an oxidation catalyst, allowing Euro 2 compliance across its production run without requiring a diesel particulate filter.
One documented concern is premature wear of the injection pump drive shaft, particularly in high-mileage units, highlighted in Daimler Service Information Bulletin 07 08 96. This issue is linked to inadequate lubrication under sustained high-load operation and extended service intervals. Later production batches incorporated revised drive coupling materials to improve durability.
Production years 1995–1998 meet Euro 2 standards (VCA UK Type Approval #VCA/EMS/5682).
The Mercedes-Benz OM612.961 is a 2,694 cc inline-five turbocharged diesel engine engineered for mid-size executive sedans (1995–1998). It combines indirect injection with a robust SOHC valvetrain and single turbocharger to deliver responsive torque and proven mechanical durability. Designed to meet Euro 2 emissions standards, it emphasizes reliability and serviceability over high specific output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,694 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-5, SOHC, 10-valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 88.0 mm × 98.0 mm | |
| Power output | 95 kW (129 PS) @ 4,200 rpm | |
| Torque | 300 Nm @ 2,400 rpm | |
| Fuel system | Bosch M-System indirect injection (pre-chamber) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | KKK K17 turbocharger with mechanical wastegate | |
| Timing system | Double-row timing chain (front-mounted) | |
| Oil type | MB 229.1 (SAE 10W-40 or 15W-40) | |
| Dry weight | 232 kg |
The turbocharged design provides strong low-RPM torque ideal for responsive driving but requires consistent oil flow to the injection pump drive system to prevent premature wear. MB 229.1 specification oil is essential due to high compression and thermal stress on the timing chain and piston rings. Oil should be changed every 15,000 km and coolant every 30,000 km to minimize corrosion and thermal fatigue. The Bosch M-System fuel pump is highly durable but sensitive to water contamination; use of quality diesel meeting EN 590 is critical. Injection pump drive shaft wear is more prevalent in units with extended oil intervals or frequent high-load operation. EGR systems require periodic inspection to prevent flow restriction and combustion inefficiency.
Oil Specs: Requires MB 229.1 specification (Daimler SIB 07 08 96). Compatible with ACEA B3/B4 standards.
Emissions: Euro 2 certification applies to all 1995–1998 models (VCA Type Approval #VCA/EMS/5682). No Euro 3 variant was produced.
Power Ratings: Measured under DIN 70020 standards. Output unchanged across production run (Daimler Group PT-1995).
Daimler Technical Information System (TIS): Docs B18724, B19019, SIB 07 08 96
VCA Type Approval Database (VCA/EMS/5682)
ISO 1585:1992 Road vehicles — Engine test code — Net power
The Mercedes-Benz OM612.961 was used across Mercedes-Benz's W124 and W210 platforms with longitudinal mounting and no licensing to other manufacturers. This engine received platform-specific adaptations-reinforced engine mounts in the W210 and revised exhaust manifolds in the W124-and from 1997 the facelifted W210 models adopted minor cooling system revisions, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-facing side of the cylinder block, near the timing cover (Daimler TIS B18724). The 8th VIN digit indicates engine type ('E' for OM612 series). Pre-1997 W124 units have a single exhaust outlet manifold; W210 models use a dual-outlet design. Critical differentiation from naturally aspirated OM612: OM612.961 includes turbocharger, intercooler (on later models), and associated plumbing. Service parts require chassis code verification - cylinder heads for W124 and W210 are not interchangeable due to different coolant passage routing and mounting points (Daimler SIB 07 08 96).
The OM612.961's primary reliability risk is injection pump drive shaft wear under sustained high-load operation, with elevated incidence in high-mileage or poorly maintained vehicles. Internal Daimler quality reports from 1996 noted a measurable rate of pump failures in units exceeding 200,000 km without timely oil changes, while VCA field data confirms fuel system faults as a top cause of drivability complaints. Extended idling and coolant neglect amplify thermal fatigue, making lubrication and cooling system diligence critical.
Analysis derived from Daimler technical bulletins (1995–1998) and UK DVSA failure statistics (1998–2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM612961.
Comprehensive technical documentation and regulatory references
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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).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
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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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