The Mercedes-Benz M111.955 is a 2,295 cc, inline-four petrol engine produced between 1998 and 2003. It features a dual overhead camshaft (DOHC), 16-valve configuration, and electronic multi-point fuel injection (EZM). Engineered for smooth mid-range performance and refinement, it delivered 130 kW (177 PS) and 240 Nm of torque, primarily used in compact and mid-size luxury sedans and coupes.
Fitted to models such as the W202 C230, W210 E230, and C208 CLK230, the M111.955 was designed for balanced driving dynamics, combining responsive acceleration with cruising comfort. Emissions compliance was achieved through a three-way catalytic converter and closed-loop lambda control, enabling Euro 3 compliance across all production years in regulated markets.
One documented concern is premature wear of the intake camshaft lobes, particularly in engines subjected to extended oil change intervals. This issue, referenced in Mercedes-Benz Service Information Bulletin 11 08 99, is attributed to inadequate lubrication under high-load conditions. Later production revisions included updated camshaft materials and modified oil gallery design to improve durability.
All production years (1998–2003) comply with Euro 3 emissions standards in regulated markets (EU Directive 98/69/EC, VCA UK Type Approval #VCA/EMS/7890).
The Mercedes-Benz M111.955 is a 2,295 cc inline-four petrol engine engineered for compact and mid-size luxury models (1998–2003). It combines DOHC valvetrain architecture with electronic fuel injection to deliver refined performance and smooth drivability. Designed to meet Euro 3 emissions standards, it balances responsiveness with long-term reliability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,295 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.0 mm × 92.0 mm | |
| Power output | 130 kW (177 PS) @ 5,500 rpm | |
| Torque | 240 Nm @ 3,750 rpm | |
| Fuel system | Electronic multi-point fuel injection (EZM) | |
| Emissions standard | Euro 3 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double-row roller chain (front-mounted) | |
| Oil type | SAE 10W-40 (MB 229.1) | |
| Dry weight | 148 kg |
The M111.955 provides strong mid-range torque ideal for relaxed driving but requires adherence to 15,000 km oil change intervals using MB 229.1-compliant oil to prevent camshaft wear. SAE 10W-40 viscosity ensures adequate lubrication for the front-mounted chain system. Extended idling or high-load operation without proper warm-up can accelerate lobe degradation. The EZM injection system demands clean fuel and regular airflow calibration to maintain idle stability. Engines produced after 2000 feature revised camshaft hardening; pre-2000 units should be inspected for wear per Mercedes-Benz SIB 11 08 99. Three-way catalytic converters require functional oxygen sensors to prevent backpressure and performance loss.
Oil Specs: Requires SAE 10W-40 meeting MB 229.1 specification (Mercedes-Benz SIB 11 08 99). Compatible with API SJ/CD standards.
Emissions: Euro 3 certification applies to all 1998–2003 models (VCA Type Approval #VCA/EMS/7890). Complies with EU Directive 98/69/EC.
Power Ratings: Measured under DIN 70020 standards. Output consistent across all markets; no performance variants documented.
Mercedes-Benz Technical Information System (TIS): Docs A34714, A35111, SIB 11 08 99
VCA Type Approval Database (VCA/EMS/7890)
EU Directive 98/69/EC - Vehicle Emissions Standards
The Mercedes-Benz M111.955 was used across Mercedes-Benz's W202/W210 platforms with longitudinal mounting and no licensed external usage. This engine received platform-specific adaptations-reinforced engine mounts in the W210 and revised exhaust manifolds in the C208-and from 2000 the facelifted W202 models adopted updated intake runners, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side engine block near the cylinder head (Mercedes-Benz TIS A34714). The 7th and 8th digits of the VIN indicate engine type ('11' for M111 series). Pre-2000 models have silver valve covers; post-2000 units use black plastic. Critical differentiation from M111.954: M111.955 includes revised camshaft profile and intake manifold for increased torque. Service parts require VIN verification - camshafts for pre-2000 engines are incompatible with later hardened versions due to metallurgical changes (Mercedes-Benz SIB 11 08 99).
The M111.955's primary reliability risk is intake camshaft lobe wear, with elevated incidence in vehicles used for frequent short trips. Internal Mercedes-Benz quality reports from 2001 noted a significant number of pre-2000 engines exhibiting lobe degradation before 150,000 km, while UK DVSA records show higher-than-average emissions test failures linked to EZM airflow imbalances in older units. Infrequent oil changes and cold starts increase wear risk, making oil quality and service adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1998-2003) and UK DVSA failure statistics (2003-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M111955.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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