The Mercedes-Benz M111.956 is a 1,998 cc, inline-four petrol engine produced between 1998 and 2002. It belongs to the M111 engine family, featuring a dual overhead camshaft (DOHC) layout and four valves per cylinder. Equipped with sequential multi-point fuel injection and an EZL ignition system, it delivers 102 kW (139 PS) at 5,500 rpm and 190 Nm of torque at 4,200 rpm, designed for mid-size passenger vehicles.
Fitted primarily to the W202 C-Class and W210 E-Class, the M111.956 was engineered for balanced performance and refinement in urban and highway driving. Its design emphasizes durability and serviceability, meeting Euro 3 emissions standards through a three-way catalytic converter, lambda feedback control, and secondary air injection, with no exhaust gas recirculation (EGR) required for petrol combustion.
One documented service concern is premature wear of the intake camshaft lobe, particularly in early production units. This issue, referenced in Mercedes-Benz Service Bulletin 07 05 98, is attributed to marginal lubrication under sustained high-load operation and extended oil change intervals. From 1999, revised camshaft materials and updated oil specifications (229.3) were introduced to improve durability.
Production years 1998–2002 comply with Euro 3 standards (VCA UK Type Approval #VCA/EMS/6789).
The Mercedes-Benz M111.956 is a 1,998 cc inline-four petrol engine engineered for mid-size platforms (1998–2002). It combines DOHC 16-valve architecture with sequential fuel injection to deliver responsive performance and moderate fuel economy. Designed to meet Euro 3 emissions standards, it prioritizes mechanical reliability and ease of maintenance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Unleaded, 95 RON min) | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 82.0 mm × 93.0 mm | |
| Power output | 102 kW (139 PS) @ 5,500 rpm | |
| Torque | 190 Nm @ 4,200 rpm | |
| Fuel system | Sequential multi-point fuel injection (KE-Jetronic derived) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.2:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Timing chain (single-row, non-interference) | |
| Oil type | 229.3 specification (SAE 10W-40) | |
| Dry weight | 142 kg |
The naturally aspirated design offers smooth throttle response ideal for daily driving but requires adherence to 15,000 km oil change intervals using 229.3-specified oil to prevent camshaft lobe wear. SAE 10W-40 viscosity ensures stable lubrication under thermal stress, particularly critical for the upper valvetrain. Extended idling or short-trip driving may accelerate carbon buildup on intake valves. Fuel quality is essential—use only 95 RON or higher unleaded petrol to maintain knock resistance and injector cleanliness. Post-1999 engines benefit from improved camshaft hardening; pre-1999 units should be inspected for lobe wear per Service Bulletin 07 05 98. The three-way catalytic converter requires regular lambda sensor checks to prevent efficiency loss.
Oil Specs: Requires MB 229.3 (10W-40) specification (Mercedes SIB 07 05 98). Supersedes ACEA A2/B2 standards.
Emissions: Euro 3 certification confirmed for all 1998–2002 production (VCA Type Approval #VCA/EMS/6789).
Power Ratings: Measured under DIN 70020 standards. Output consistent across all markets (Mercedes TIS Doc. A11406).
Mercedes-Benz Technical Information System (TIS): Docs A11181, A11206, A11313, SIB 07 05 98
VCA Type Approval Database (VCA/EMS/6789)
DIN Standards: DIN 70020 Engine Power Measurement
The Mercedes-Benz M111.956 was used across Mercedes-Benz's W202/W210 platforms with longitudinal mounting in rear-wheel-drive applications. This engine received platform-specific adaptations—shorter intake manifolds in the W202 and revised exhaust routing in the W210—and from 2000 the facelifted W202 models adopted updated lambda control, creating 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 exhaust manifold (Mercedes TIS A11181). The 8th VIN digit indicates engine type ('M' for M111 series). Pre-1999 models have silver valve covers with black plastic cam covers; post-1999 units use black valve covers. Critical differentiation from M111.950: M111.956 has a distributorless EZL ignition system with coil packs mounted on the intake manifold, while M111.950 uses a conventional distributor. Service parts require production date verification—camshafts for engines before 08/1999 are incompatible with later units due to material upgrade (Mercedes SIB 07 05 98).
The M111.956's primary reliability risk is intake camshaft lobe wear on early builds, with elevated incidence in high-mileage urban use. Internal Mercedes quality reports from 1999 indicated a notable share of pre-1999 engines showing lobe degradation before 150,000 km, while UK DVSA records show increased catalytic converter failures in vehicles with delayed lambda sensor servicing. Extended oil intervals and low-RON fuel exacerbate wear and knock risk, making oil quality and fuel specification adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1998-2002) and UK DVSA failure statistics (1999-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M111956.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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