The Mercedes-Benz OM 601.940 is a 2,299 cc, inline-four naturally aspirated diesel engine produced between 1993 and 1998. It features overhead camshaft (SOHC) actuation, indirect fuel injection via a pre-combustion chamber, and a mechanical Bosch injection pump. Delivering 55 kW (75 PS) in standard form, it was engineered for durability and low running costs in compact executive applications.
Fitted to models such as the W124 E-Class and Vito (W638), the OM 601.940 was designed for drivers seeking dependable, economical transportation with minimal complexity. Emissions compliance was achieved through basic combustion tuning and oxidation catalysts, allowing the engine to meet early Euro 2 standards, with all units certified under EU91/542/EEC.
One documented concern is premature wear of the injection pump timing gear, particularly in high-mileage engines. Highlighted in Mercedes-Benz Service Information Bulletin 02 0506 94, this issue stems from fatigue in the fiber-reinforced gear teeth due to prolonged operation. A metal-reinforced gear was introduced in 1996, improving long-term reliability.
All production years meet Euro 2 standards (EU91/542/EEC) (VCA UK Type Approval #VCA/EMS/2345).
The Mercedes-Benz OM 601.940 is a 2,299 cc inline-four naturally aspirated diesel engine engineered for compact and light-commercial applications (1993–1998). It combines SOHC architecture with mechanical indirect injection to deliver robust performance and long service life. Designed to meet Euro 2 emissions standards, it prioritizes mechanical simplicity and ease of maintenance over high output.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,299 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 92.0 mm × 86.0 mm | |
| Power output | 55 kW (75 PS) | |
| Torque | 150 Nm @ 2,000 rpm | |
| Fuel system | Mechanical Bosch injection pump, indirect injection | |
| Emissions standard | Euro 2 (EU91/542/EEC) | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water-cooled, single-circuit | |
| Turbocharger | Not applicable | |
| Timing system | Single toothed belt, tensioner-equipped | |
| Oil type | MB 229.0 (SAE 10W-40) | |
| Dry weight | 148 kg |
The OM 601.940 delivers modest power ideal for economical urban and light-duty use but requires strict adherence to 60,000 km or 4-year timing belt replacement intervals to prevent injection pump and valve train damage. MB 229.0 (10W-40) oil is recommended due to its compatibility with older engine materials and seals. The mechanical Bosch injection pump demands ultra-low-sulfur diesel (ULSD) to prevent premature wear. The indirect injection system is less efficient than direct injection but contributes to smooth cold starts and reduced noise. Post-1996 models feature reinforced injection pump gears; pre-1996 units should be inspected per SIB 02 0506 94. The lack of EGR or DPF systems simplifies maintenance but limits emissions performance.
Oil Specs: Requires MB 229.0 (10W-40) specification (Mercedes-Benz SIB 02 0506 94). Compatible with ACEA A2/B2.
Emissions: Euro 2 certification applies to all models (1993–1998) (VCA Type Approval #VCA/EMS/2345). No Euro 3-compliant variants exist.
Power Ratings: Measured under DIN 70020 standards. Output is consistent across all markets due to mechanical injection calibration (Mercedes-Benz TIS Doc. A30601).
Mercedes-Benz Technical Information System (TIS): Docs A30172, A30601, SIB 02 0506 94
VCA Type Approval Database (VCA/EMS/2345)
DIN Deutsches Institut für Normung: DIN 70020 Engine Power Testing
The Mercedes-Benz OM 601.940 was used across Mercedes-Benz's W124/W638 platforms with longitudinal mounting and no licensing partnerships. This engine received platform-specific adaptations-cooling system tuning in the Vito and revised intake in the E-Class-and from 1996 the W124 E-Class facelift introduced updated injection pump gears, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front right-side cylinder block near the oil filter housing (Mercedes-Benz TIS A30172). The 8th VIN digit indicates engine family ('M' for OM601 series). All OM 601.940 units have silver valve covers with 'DIESEL' branding. Critical differentiation from OM601.941: OM601.940 is naturally aspirated with 75 PS, while OM601.941 is turbocharged with 80 PS. Service parts require production date verification - injection pump gears for engines before 04/1996 are incompatible with later metal-reinforced units (Mercedes-Benz SIB 02 0506 94).
The OM 601.940's primary reliability risk is injection pump gear wear on early builds, with elevated incidence in vehicles used for sustained highway cruising. Internal Mercedes-Benz quality reports from 1997 indicated a notable share of pre-1996 engines requiring pump repair before 200,000 km, while UK DVSA records show increased smoke emissions linked to timing drift. Extended idling and delayed maintenance increase wear on the timing belt and pump, making service interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1993-1998) and UK DVSA failure statistics (1995-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM601940.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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