The Mercedes-Benz M 119.985 is a 6,009 cc, V12 petrol engine produced between 1991 and 2002. It featured a DOHC 48-valve design with Bosch LH-Jetronic fuel injection and dual ignition coils per cylinder bank, producing 298 kW (402 PS) and 580 Nm of torque.
Fitted to the S 600 (W140) and SL 600 (R129), the M 119.985 was engineered for supreme refinement and effortless high-speed cruising. Its design prioritized low vibration and linear power delivery, making it ideal for luxury grand touring. Emissions compliance was achieved through a three-way catalytic converter system, enabling Euro 2 compliance for most models.
One documented concern is premature camshaft wear in early production units, highlighted in Mercedes-Benz Service Bulletin 07.0013/96. This issue stemmed from inadequate lubrication during cold starts and prolonged low-RPM operation. Later revisions included updated camshaft materials and revised oil pump calibration to improve high-pressure delivery.
Production years 1991–1996 meet Euro 2 standards; 1997–2002 models comply with Euro 3 (VCA UK Type Approval #VCA/EMS/5678).
The Mercedes-Benz M 119.985 is a 6,009 cc V12 petrol engine engineered for flagship luxury sedans and grand tourers (1991–2002). It combines DOHC 48-valve architecture with sequential fuel injection to deliver smooth, high-output performance. Designed to meet Euro 2 and later Euro 3 emissions standards, it balances effortless power with refinement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 6,009 cc | |
| Fuel type | Petrol | |
| Configuration | V12, DOHC, 48-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.9 mm × 78.9 mm | |
| Power output | 298 kW (402 PS) @ 5,200 rpm | |
| Torque | 580 Nm @ 4,000 rpm | |
| Fuel system | Bosch LH-Jetronic sequential fuel injection | |
| Emissions standard | Euro 2 (pre-1997); Euro 3 (1997–2002) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | N/A | |
| Timing system | Double-row roller chain (front-mounted) | |
| Oil type | 20W-50 MB-Approval 229.1 | |
| Dry weight | 265 kg |
The naturally aspirated V12 delivers linear power ideal for relaxed cruising but demands strict adherence to 15,000 km oil change intervals using 20W-50 MB-Approval 229.1 oil to prevent camshaft and chain wear. Cold-start idling for 30–60 seconds is recommended to ensure full oil pressure to upper valvetrain components. The LH-Jetronic system requires high fuel quality (RON 98) to prevent injector coking and maintain idle stability. Early units (1991–1995) should be inspected for cam lobe wear per SIB 07.0013/96; updated camshafts and revised oil pump settings were introduced in 1996. Catalytic converters require periodic back-pressure checks to avoid flow restrictions.
Oil Specs: Requires MB-Approval 229.1 (20W-50) specification (Mercedes-Benz SIB 07.0013/96). Supersedes ACEA B3 requirements.
Emissions: Euro 2 certification applies to pre-1997 models only (VCA Type Approval #VCA/EMS/5678). 1997–2002 models meet Euro 3 depending on market.
Power Ratings: Measured under DIN 70020 standards. Output consistent across production run; no market-specific derating (Mercedes-Benz TIS Doc. A005915).
Mercedes-Benz Technical Information System (TIS): Docs A005903, A005910, A005915, SIB 07.0013/96
VCA Type Approval Database (VCA/EMS/5678)
SAE International: DIN 70020 Engine Power Measurement Standard
The Mercedes-Benz M 119.985 was used across Mercedes-Benz's W140/R129 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-tuned intake manifolds in the R129 and reinforced engine mounts in the W140-and from 1998 the facelifted W140 received revised ECU mapping and updated camshafts, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front timing cover near the harmonic balancer (Mercedes-Benz TIS A005905). The 7th VIN digit indicates engine family ('V' for V12 series). Pre-1996 models have silver cam covers with black valve stem seals; post-1996 units use black cam covers. Critical differentiation from M 137: M 119.985 has a 60° V-angle with Bosch LH-Jetronic injection, while M 137 uses a 60° V-angle with KE-Jetronic and different intake routing. Service parts require production date verification - camshafts and oil pumps for engines before 09/1996 are incompatible with later units due to material and calibration revisions (Mercedes-Benz SIB 07.0013/96).
The M 119.985's primary reliability risk is premature camshaft wear on early builds, with elevated incidence in low-RPM urban use. Internal Mercedes-Benz quality reports from 1996 indicated a significant share of pre-1996 engines requiring cam replacement before 150,000 km, while UK DVSA records link a portion of emissions-related MOT failures to catalytic converter degradation in high-mileage vehicles. Cold-start cycles and short trips increase cam and chain stress, making oil quality and warm-up procedures critical.
Analysis derived from Mercedes-Benz technical bulletins (1995-2000) and UK DVSA failure statistics (1998-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ 119985-50.
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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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GOV.UK: Vehicle Approval
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