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,…
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 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.
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.
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The M112.943 offers smooth performance and strong torque, but remains prone to intake camshaft lobe wear if maintenance intervals are extended or incorrect oil is used. Later M112 series revisions show improved durability when serviced correctly. Regular oil changes using MB 229.3 (10W-60) specification oil significantly enhance long-term reliability. Well-maintained units can exceed 200,000 km without major issues.
Primary concerns include intake camshaft lobe wear, cooling system failures (thermostat/hoses), lambda sensor degradation, and fuel injector clogging. These are documented in Mercedes-Benz Service Bulletin 07-0501-98 and TIS documentation. Preventive maintenance, especially oil and coolant service, greatly reduces the likelihood of these failures.
The M112.943 was used in the Mercedes-Benz E-Class (W210) E 280 (1997–2000) and CLK (C208) CLK 280 (1997–2000). It was not exported to North America and remained exclusive to European and select international markets. All applications feature longitudinal mounting and share platform-specific ECU tuning.
Limited tuning potential exists due to its naturally aspirated design. ECU remapping can yield modest gains (~15–20 PS) by optimizing fuel and ignition maps. However, significant power increases require internal modifications. As the engine was not designed for forced induction, adding a supercharger or turbocharger involves substantial engineering and is not supported by OEM documentation.
In combined driving, the M112.943 achieves approximately 9.5–11.5 L/100km (25–30 mpg UK). Highway efficiency improves to ~7.5 L/100km (38 mpg UK), while city driving may reach 13.0 L/100km (22 mpg UK). Real-world consumption depends on driving style and vehicle weight. Fuel quality per EN 228 ensures optimal injector and catalyst longevity.
No. The M112.943 features a non-interference valvetrain design. If the timing chain fails or jumps, the pistons will not contact the valves, preventing catastrophic internal damage. However, the engine will cease to run, and repair of the chain and tensioner is still required. This design improves service safety but does not reduce the importance of regular inspection.
Mercedes-Benz specifies MB 229.3 (SAE 10W-60) or equivalent ACEA A3/B3 oil for the M112.943. Oil changes should occur every 15,000 km or annually. Using incorrect viscosity or lower-specification oil increases the risk of camshaft lobe wear, particularly in high-load conditions. Always verify oil meets MB 229.3 standards before use.
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Regulation (EC) No 715/2007
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