The Mercedes-Benz OM 603.913 is a 3,498 cc, inline-six, naturally aspirated diesel engine produced between 1995 and 2002. It was part of the final generation of Mercedes-Benz's large-displacement inline-six diesel engines, featuring a Bosch M-System inline injection pump. Renowned for smoothness, durability, and high torque output, it delivered 100 kW (136 PS) and 350 Nm, making it ideal for executive sedans and long-distance comfort.
Fitted primarily to the W140 S-Class and W210 E-Class models, the OM 603.913 was engineered for refinement and sustained highway performance. It met Euro 2 emissions standards through mechanical precision and combustion tuning, without requiring EGR or DPF systems. This design prioritized reliability, low maintenance, and quiet operation in luxury vehicle applications.
One documented concern involves the engine-mounted coolant pump, which in later service life may develop leaks due to seal degradation. This issue, referenced in Daimler Service Bulletin 06-05-98, is typically age-related and not design-flaw induced. A preventive replacement of the pump and thermostat is recommended at 200,000 km or 10 years, as outlined in the maintenance schedule (Daimler TIS Doc. 603.913-20-01).
Production years 1995–2002 meet Euro 2 standards (VCA UK Type Approval #VCA/EMS/5679).
The Mercedes-Benz OM 603.913 is a 3,498 cc inline-six diesel engine engineered for flagship sedans and executive wagons (1995–2002). It combines mechanical Bosch M-System injection with a robust cast-iron block and seven-main-bearing crankshaft to deliver smooth power delivery and mechanical resilience. Designed to meet Euro 2 standards, it emphasizes refinement and longevity over modern emissions complexity.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,498 cc | |
| Fuel type | Diesel | |
| Configuration | Inline-6, SOHC, 12-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 94.0 mm × 84.0 mm | |
| Power output | 100 kW (136 PS) @ 4,200 rpm | |
| Torque | 350 Nm @ 2,200 rpm | |
| Fuel system | Bosch M-System inline injection pump (mechanical) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 22.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Gear-driven (no service interval) | |
| Oil type | MB 229.1 (SAE 15W-40) | |
| Dry weight | 245 kg |
The naturally aspirated inline-six layout provides smooth, linear power delivery ideal for relaxed cruising and load-carrying. Due to the gear-driven timing system, no timing belt or chain replacement is required, significantly reducing long-term maintenance costs. MB 229.1 (15W-40) oil is essential to maintain proper lubrication under high compression and thermal loads. The mechanical injection system is highly resistant to fuel contamination but requires periodic pump calibration. Coolant pump and thermostat should be replaced preventively at 200,000 km or 10 years per Daimler SIB 06-05-98 to avoid leaks. Absence of EGR/DPF eliminates regeneration issues but requires attention to injector nozzle condition for optimal combustion.
Oil Specs: Requires MB 229.1 (15W-40) specification (Daimler SIB 06-05-98). Compatible with ACEA B3/B4.
Emissions: Euro 2 certification applies to all models (1995–2002) (VCA Type Approval #VCA/EMS/5679).
Power Ratings: Measured under DIN 70020 standards. Output consistent across production run with no market-specific variants.
Daimler Technical Information System (TIS): Docs B30561, B31246, SIB 06-05-98
VCA Type Approval Database (VCA/EMS/5679)
SAE International: DIN 70020 Engine Power Testing Standard
The Mercedes-Benz OM 603.913 was used across Mercedes-Benz's W140 and W210 platforms with longitudinal mounting. This engine received platform-specific adaptations-reinforced mounts in the W140 and revised accessory drives in the W210-and from 1997 the facelifted W210 models adopted revised engine management linkages, creating minor 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 B30790). The 8th VIN digit indicates engine type ('H' for OM 603 series). Pre-1997 W140 models have a mechanical throttle linkage; post-1997 W210 units use a revised cable routing. Critical differentiation from turbocharged variants: OM 603.913 lacks a turbocharger and intercooler, with a simpler exhaust manifold. Service parts require chassis code verification - coolant pumps for W140 and W210 are not interchangeable due to mounting differences (Daimler SIB 06-05-98).
The OM 603.913's primary reliability risk is coolant pump seal failure in high-mileage or aged vehicles, with elevated incidence in models over 15 years old. Daimler field reports from 2003 indicated a notable share of W210 E350D units requiring pump replacement after 200,000 km, while UK DVSA records show minimal emissions-related failures due to the absence of EGR/DPF systems. Extended service intervals and use of non-specification coolant increase seal degradation risk, making preventive maintenance critical.
Analysis derived from Daimler technical bulletins (1995-2005) and UK DVSA failure statistics (1998-2010). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ OM603913.
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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
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DVLA: Engine Changes & MoT
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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
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