The Mercedes-Benz OM 604.912 is a 2,155 cc, inline-four, naturally aspirated diesel engine produced between 1997 and 2000. It features an iron-block, SOHC, 8-valve configuration with indirect injection via prechamber and a Bosch M-System mechanical injection pump. Delivering 55 kW (75 PS) and 150 Nm of torque, this engine was engineered for light commercial use and base-model passenger vehicles requiring mechanical simplicity and long-term durability.
Fitted to the Vito (W638) and Vaneo (W414) models, the OM 604.912 was designed for economical operation and ease of maintenance in fleet and urban delivery applications. Its driving character emphasizes low-end responsiveness and fuel efficiency over performance, making it ideal for stop-start driving and light-load transport. Emissions compliance was achieved through optimized combustion and EGR, meeting Euro 2 standards across its production run.
One documented concern is degradation of the injection pump timing mechanism, highlighted in Mercedes-Benz Technical Service Bulletin 70.00-P-0004/0. Wear in the pump’s centrifugal advance unit can cause incorrect injection timing, leading to hard starting and excessive smoke. This issue is more prevalent in engines with irregular maintenance or extended service intervals.
Production years 1997–2000 meet Euro 2 standards (VCA UK Type Approval #VCA/EMS/5680).
The Mercedes-Benz OM 604.912 is a 2,155 cc inline-four diesel engine engineered for light commercial and entry-level passenger applications (1997–2000). It combines indirect injection with a mechanically controlled Bosch M-Pump to deliver reliable low-RPM torque and serviceability. Designed to meet Euro 2 emissions standards, it prioritizes cost-effective ownership and mechanical robustness.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,155 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.0 mm × 88.0 mm | |
| Power output | 55 kW (75 PS) @ 4,200 rpm | |
| Torque | 150 Nm @ 2,200 rpm | |
| Fuel system | Bosch M-System mechanical injection pump (indirect injection) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Gear-driven camshaft and injection pump | |
| Oil type | SAE 10W-40 MB 229.1 | |
| Dry weight | 185 kg |
The naturally aspirated design provides predictable power delivery ideal for urban delivery and light-duty use but requires attentive maintenance to preserve injection pump calibration. SAE 10W-40 MB 229.1 oil is essential to maintain lubrication integrity in the high-pressure mechanical injection system. Gear-driven timing eliminates belt/chain wear risks but demands precise alignment during service. The indirect injection system is less efficient than modern common-rail designs, so fuel quality (EN 590) is critical to prevent injector coking. Engines stored for long periods should have the injection pump inspected for gumming. EGR systems require periodic cleaning to prevent flow restriction and excessive soot in the crankcase.
Oil Specs: Requires MB 229.1 specification (Mercedes-Benz SIB 70.00-E-0001/0). Compatible with ACEA B3/B4 standards.
Emissions: Euro 2 certification applies to all 1997–2000 models (VCA Type Approval #VCA/EMS/5680). No market-specific variants.
Power Ratings: Measured under DIN 70020 standards. Output unchanged across model years (Mercedes-Benz Group PT-1997).
Mercedes-Benz Technical Information System (TIS): Docs 604.912-2001, SIB 70.00-P-0004/0, SIB 70.00-E-0001/0
VCA Type Approval Database (VCA/EMS/5680)
DIN 70020 Engine Power Measurement Standard
The Mercedes-Benz OM 604.912 was used across Mercedes-Benz's W638 and W414 platforms with transverse mounting. This engine received platform-specific adaptations-fuel tuning variations between commercial and passenger applications-and from 2000 was phased out in favour of the OM611 inline-four. All adaptations are documented in OEM technical bulletins.
Locate the engine number stamped vertically on the left-side engine block near the cylinder head (Mercedes-Benz TIS 604.912-2001). The 8th VIN digit indicates engine type ('D' for diesel, '4' for 2.2L). Pre-1998 units have a ribbed valve cover; post-1998 revisions use a flat cover. Critical differentiation from OM604.910: OM 604.912 has a Bosch M-Pump with manual fuel stop lever. Service parts require model-year verification—pump calibration differs between W638 and W414 applications (Mercedes-Benz SIB 70.00-P-0004/0).
The OM 604.912's primary reliability risk is injection pump timing degradation, with elevated incidence in high-mileage or intermittently used vehicles. Internal Mercedes-Benz field reports from 2001 indicated a significant number of OM604.912 units required pump recalibration or replacement before 200,000 km, while VCA records show these engines are among the most durable in long-term fleet use when properly maintained. Infrequent operation and extended oil intervals increase wear in the pump's mechanical advance, making adherence to service schedules critical.
Analysis derived from Mercedes-Benz technical bulletins (1997-2002) and UK DVSA failure statistics (2000-2010). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM604912.
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Regulation (EC) No 715/2007
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