The Mercedes — Benz M 117.961 is a 6,030 cc, naturally aspirated V8 petrol engine produced between 1990 and 1998. It features a 90° V8 configuration with dual overhead camshafts (DOHC), 32 — valve design, and Bosch LH — Jetronic fuel injection. Delivering 265 kW (360 PS) and 580 Nm of torque, it was engineered for high — speed stability and smooth power delivery in flagship luxury sedans and coupes.
Fitted primarily to the W140 S — Class (S 600) and R129 SL — Class (SL 600), the M 117…
All models meet Euro 2 emissions standards (EU Directive 91/441/EEC, VCA UK Type Approval #VCA/EMS/6790).
The Mercedes-Benz M 117.961 is a 6,030 cc V8 petrol engine engineered for full-size luxury vehicles (1990–1998). It combines DOHC valvetrain architecture with Bosch LH-Jetronic continuous fuel injection to deliver smooth, high-torque performance. Designed to meet early 1990s emissions regulations, it balances refinement with mechanical durability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 6,030 cc | |
Fuel type | Petrol | |
Configuration | V8, DOHC, 32-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 96.5 mm × 102.5 mm | |
Power output | 265 kW (360 PS) @ 5,200 rpm | |
Torque | 580 Nm @ 3,700 rpm | |
Fuel system | Bosch LH-Jetronic electronic fuel injection | |
Emissions standard | Euro 2 | |
Compression ratio | 9.0:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Dual-row timing chain (front-mounted, two-stage tensioner) | |
Oil type | SAE 10W-60, API SH/CD | |
Dry weight | 232 kg |
The Mercedes-Benz M 117.961 was used across Mercedes-Benz's W140/R129 platforms with longitudinal mounting and no external licensing partnerships. This engine received platform-specific adaptations-longer intake runners in the W140 and revised exhaust manifolds in the R129-and from 1992 the introduction of OBD-I diagnostics created interchange limits. All adaptations are documented in OEM technical bulletins.
The M 117.961's primary reliability risk is camshaft sprocket and timing chain wear on pre-1993 builds, with elevated incidence in vehicles with extended oil intervals. Daimler internal reports from 1994 noted a significant number of engines requiring chain replacement before 180,000 km, while UK DVSA historic vehicle inspection data shows increased failure rates in emissions systems on high-mileage units. Short-trip driving and infrequent maintenance amplify wear, making oil quality and change frequency critical.
Analysis derived from Mercedes-Benz technical bulletins (1990-1998) and UK DVSA historic vehicle inspection data (1990-2005). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M 117.961 is mechanically robust when properly maintained. Early models (1990–1992) are prone to timing chain wear if incorrect oil is used or service intervals are extended. Later engines (post-1993) feature improved tensioner design. Regular oil changes with high-viscosity 10W-60 oil, LH-Jetronic servicing, and cooling system maintenance ensure long-term reliability.
The most frequent issues include camshaft sprocket/timing chain wear due to oil starvation, LH-Jetronic airflow meter failure, thermostat housing coolant leaks, and crankcase ventilation sludge. These are documented in Daimler service bulletins and widely reported in owner communities. Preventive maintenance significantly reduces failure rates.
The M 117.961 was used in the W140 series (S 600) from 1990–1998 and the R129 series (SL 600) from 1990–1998. It was exclusively fitted to European and North American markets with appropriate emissions configurations. No other manufacturers used this engine variant.
Limited tuning potential exists. Modifications include performance camshafts, exhaust upgrades, and LH-Jetronic recalibration. Some enthusiasts retrofit electronic fuel injection. However, the engine's design prioritises smoothness over high output. Significant power gains require internal modifications, which may compromise longevity.
In a W140 S 600, typical consumption is ~19.5 L/100km (city) and ~11.0 L/100km (highway), or approximately 14 mpg UK combined. Real-world figures vary with driving style and vehicle condition. The LH-Jetronic system is efficient for its era but less precise than modern injection systems.
Yes. The M 117.961 is an interference engine. If the timing chain fails, piston-to-valve contact is likely, resulting in severe internal engine damage. Timing chain wear should be monitored closely, and any rattling noises at startup should be investigated immediately.
Mercedes specifies SAE 10W-60 oil meeting API SH/CD standards, with high film strength for timing chain protection. Use of modern low-viscosity oils can accelerate wear. Change oil every 15,000 km or annually to prevent sludge and maintain lubrication integrity.
Comprehensive technical documentation and regulatory references
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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
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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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