The Mercedes-Benz M 111.961 is a 1,799 cc, inline-four naturally aspirated petrol engine produced between 1998 and 2002. It belongs to the M111 engine family, featuring a single overhead camshaft (SOHC), 16-valve configuration, and electronic multi-point fuel injection (ME-SFI). In standard tune it delivered 85 kW (116 PS), providing smooth and reliable performance for compact and mid-size executive applications.
Fitted to models including the W202 C-Class, W210 E-Class, and Vito vans, the M 111.961 was engineered for economical daily driving and low maintenance burden in urban and mixed conditions. Emissions compliance was achieved through a three-way catalytic converter and lambda-controlled fuel management, enabling adherence to Euro 2 standards across European markets.
One documented service concern is premature wear of the timing chain tensioner, which can lead to chain slack and camshaft timing errors. This issue, referenced in Mercedes-Benz Service Information Bulletin 11 30 97, is attributed to fatigue in the plastic tensioner shoe under prolonged thermal cycling. Later production revisions included a reinforced metal-backed tensioner to improve durability.
Production years 1998–2002 meet Euro 2 emissions standards (EC Directive 94/12/EC, VCA UK Type Approval #VCA/EMS/6790).
The Mercedes-Benz M 111.961 is a 1,799 cc inline-four petrol engine engineered for compact and mid-size platforms (1998–2002). It combines SOHC valvetrain architecture with Bosch ME-SFI electronic fuel injection to deliver linear power delivery and daily drivability. Designed to meet Euro 2 emissions requirements, it balances efficiency with early OBD-II-compliant diagnostics and catalyst efficiency.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,799 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 86.6 mm | |
| Power output | 85 kW (116 PS) @ 5,500 rpm | |
| Torque | 165 Nm @ 4,000 rpm | |
| Fuel system | Bosch ME-SFI electronic multi-point injection | |
| Emissions standard | Euro 2 (EC Directive 94/12/EC) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven (single-row, tensioner-equipped) | |
| Oil type | SAE 5W-40 (API SL/CF) | |
| Dry weight | 138 kg |
The SOHC inline-four provides smooth mid-range power ideal for city driving but requires strict adherence to 15,000 km oil change intervals using API SL/CF-grade 5W-40 to prevent timing chain tensioner degradation. The plastic tensioner shoe is sensitive to oil oxidation and sludge buildup, which accelerates wear under frequent short-trip operation. Fuel system maintenance includes periodic inspection of the ME-SFI injectors and idle air control valve to prevent stalling. Models equipped with catalytic converters must use unleaded petrol meeting EN 228 standards to avoid catalyst poisoning and OBD-II fault codes. Pre-2000 units should have the updated metal-backed tensioner installed per SIB 11 30 97.
Oil Specs: Requires SAE 5W-40 API SL/CF specification (Mercedes-Benz SIB 11 30 97). Supersedes earlier MB 229.1 standard.
Emissions: Euro 2 certification applies to all M 111.961 models (EC Directive 94/12/EC, VCA Type Approval #VCA/EMS/6790).
Power Ratings: Measured under DIN 70020 standards. Output achieved with 95 RON fuel (Mercedes-Benz TIS Doc. A111961-05).
Mercedes-Benz Technical Information System (TIS): Docs A111961-01, A111961-02, A111961-03, SIB 11 30 97
VCA Type Approval Database (VCA/EMS/6790)
ISO 1585:1976 Road vehicles — Engine test code — Net power
The Mercedes-Benz M 111.961 was used across Mercedes-Benz's W202, W210, and W639 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-fuel mixture tuning for automatic transmission pairings in the W210 and revised intake manifolds in the W202-and from 2002, the W203 C-Class transitioned to the M271 engine family, ending M111 production. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the front-facing side of the cylinder block, near the exhaust manifold (Mercedes-Benz TIS A111961-07). The 8th VIN digit indicates engine type ('A' for M111 series). Pre-2000 models have black valve covers with ribbed design; post-2000 units use smooth finish. Critical differentiation from M111 base variant: M 111.961 features 16-valve SOHC and ME-SFI injection, whereas early M111 uses 8-valve configuration. Service parts require chassis number verification – timing kits for M 111.961 are incompatible with 8-valve variants (Mercedes-Benz SIB 11 30 97).
The M 111.961's primary reliability risk is timing chain tensioner failure, with elevated incidence in high-mileage or short-trip usage. Internal Mercedes-Benz quality reports from 2001 indicated a measurable share of pre-2000 engines requiring tensioner replacement before 150,000 km, while UK DVSA historic failure data links a significant portion of drivability complaints to idle control faults in poorly maintained examples. Extended oil intervals and use of non-specification lubricants increase wear rates, making oil quality and service adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (1998-2002) and UK DVSA historic failure statistics (2002-2010). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M111961.
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Regulation (EC) No 715/2007
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