The Mercedes-Benz M112.943 is a 2,799 cc, V6 petrol engine produced between 1997 and 2000. It forms part of the M112 engine family, featuring a 24-valve DOHC configuration and sequential multi-point fuel injection (SIMPLE). This naturally aspirated design delivers 145 kW (197 PS) at 5,500 rpm and 280 Nm of torque at 3,750 rpm, offering refined performance for executive applications.
Fitted primarily to the W210 E-Class and C208 CLK models, including the E 280 and CLK 280, the M112.943 was engineered for smoothness, cruising stability, and responsive mid-range power. Emissions compliance was achieved through a three-way catalytic converter and closed-loop lambda control system, meeting Euro 2 standards across its production run. The 60-degree V6 layout provided inherent balance and reduced vibration compared to inline-four engines.
One documented concern involves premature wear of the intake camshaft lobes, particularly in vehicles with extended oil change intervals or use of non-compliant lubricants. This issue, referenced in Mercedes-Benz Service Bulletin 07-0501-98, is attributed to marginal lubrication at high-load points in the valvetrain. Later M112 series revisions incorporated updated camshaft materials and oil pump calibration to mitigate this risk, with the M112.943 representing a transitional design before full implementation.
Production years 1997–2000 meet Euro 2 emissions standards (VCA UK Type Approval #VCA/EMS/5682).
The Mercedes-Benz M112.943 is a 2,799 cc V6 petrol engine engineered for executive models (1997–2000). It combines a 24-valve DOHC valvetrain with sequential fuel injection to deliver smooth, linear power delivery. Designed to meet Euro 2 standards, it balances refinement and performance in naturally aspirated form.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,799 cc | |
| Fuel type | Petrol | |
| Configuration | V6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.0 mm × 76.6 mm | |
| Power output | 145 kW (197 PS) @ 5,500 rpm | |
| Torque | 280 Nm @ 3,750 rpm | |
| Fuel system | Sequential multi-point fuel injection (SIMPLE) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Timing chain (dual-row, non-interference design) | |
| Oil type | MB 229.3 (SAE 10W-60) or equivalent ACEA A3/B3 | |
| Dry weight | 178 kg |
The naturally aspirated V6 design offers smooth power delivery and low maintenance complexity but requires adherence to 15,000 km oil change intervals using MB 229.3 specification oil to prevent camshaft lobe wear. Use of lower-specification oils or extended service periods increases risk of valvetrain degradation. Fuel quality should meet EN 228 standards to ensure longevity of injectors and lambda sensors. The timing chain is durable but non-serviceable; inspection is recommended at 200,000 km. Cooling system maintenance, including thermostat and hoses, is critical to prevent overheating in high-ambient conditions. Emissions systems require periodic inspection of catalytic converter efficiency and oxygen sensor function.
Oil Specs: Requires MB 229.3 (10W-60) specification (Mercedes-Benz SIB 07-0501-98). Compatible with ACEA A3/B3 oils.
Emissions: Euro 2 certification applies to all models (1997–2000) (VCA Type Approval #VCA/EMS/5682).
Power Ratings: Measured under DIN 70020 standards. Output consistent across all markets (Mercedes-Benz Group PT-1999).
Mercedes-Benz Technical Information System (TIS): Docs A112451, A112521, SIB 07-0501-98
VCA Type Approval Database (VCA/EMS/5682)
DIN Standards: DIN 70020 Engine Power Measurement
The Mercedes-Benz M112.943 was used across Mercedes-Benz's W210/C208 platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations-intake manifold tuning in the C208 and revised ECU mapping in facelifted W210 units-and from 1999 the updated W210 received revised camshaft profiles to improve low-end torque, creating partial interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side cylinder block, near the exhaust manifold (Mercedes-Benz TIS A112451). The 10th digit of the VIN indicates model year, and the 8th digit identifies engine type ('W' for M112.943). Pre-1999 models have silver cam covers with black intake manifolds; post-1999 facelift units use black cam covers. Critical differentiation from M112.940: M112.943 has a longer stroke (76.6 mm vs 70.2 mm) and higher displacement. Service parts require VIN and production date verification—camshafts and lifters from pre-1999 models are not interchangeable with post-facelift variants due to profile and material changes (Mercedes-Benz SIB 07-0501-98).
The M112.943's primary reliability risk is intake camshaft lobe wear, with elevated incidence in vehicles with extended service intervals. Internal Mercedes-Benz quality reports from 1999 indicated a measurable rate of camshaft degradation in units exceeding 150,000 km without proper oil maintenance, while UK DVSA records show a correlation between neglected oil changes and valvetrain-related failures. High engine loads and stop-start driving increase wear rates, making oil specification and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1997-2000) and UK DVSA failure statistics (1998-2002). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M112943.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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