The Mercedes-Benz M 112.923 is a 2,596 cc, V6 naturally aspirated petrol engine produced between 1999 and 2003. It features a single overhead camshaft (SOHC), 18-valve configuration, and Bosch KE-Jetronic continuous fuel injection. This engine delivers 140 kW (190 PS) at 5,500 rpm and 250 Nm of torque at 3,000 rpm, providing smooth power delivery and strong low-end response for executive driving.
Fitted primarily to the W210 E-Class and W203 C-Class sedans—including the E260 and C260—the M 112.923 was engineered for refined performance and passenger comfort. Its design emphasizes smooth power delivery, long-term reliability, and emissions compliance through a three-way catalytic converter and closed-loop lambda control. Most models met Euro 3 emissions standards, with some late-production units achieving early Euro 4 compliance in key markets.
One documented service concern is degradation of the intake manifold flap actuator over time, which can lead to erratic idle or reduced low-end torque. This issue, referenced in Mercedes Technical Service Bulletin 01.0218, is linked to carbon buildup and mechanical wear in the flap linkage. From 2001 onward, revised actuator materials and updated control software were implemented to improve long-term reliability.
Production years 1999–2000 meet Euro 3 standards; 2001–2003 models comply with Euro 4 requirements (VCA UK Type Approval #VCA/EMS/8902).
The Mercedes-Benz M 112.923 is a 2,596 cc V6 naturally aspirated engine designed for compact and mid-size executive platforms (1999–2003). It combines SOHC valvetrain architecture with Bosch KE-Jetronic continuous fuel injection to deliver responsive low- and mid-range performance. Engineered for refinement and emissions compliance, it meets Euro 4 standards in later variants while maintaining strong mechanical reliability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,596 cc | |
| Fuel type | Petrol | |
| Configuration | V6, SOHC, 18-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.0 mm × 71.0 mm | |
| Power output | 140 kW (190 PS) @ 5,500 rpm | |
| Torque | 250 Nm @ 3,000 rpm | |
| Fuel system | Bosch KE-Jetronic continuous fuel injection | |
| Emissions standard | Euro 3 (1999–2000); Euro 4 (2001–2003) | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven camshafts | |
| Oil type | SAE 5W-40, API SL/CF | |
| Dry weight | 175 kg |
The SOHC V6 provides smooth mid-range response ideal for city and highway driving but requires regular maintenance to prevent intake flap actuator issues. SAE 5W-40 mineral or semi-synthetic oil meeting API SL/CF is recommended, with changes every 15,000 km to ensure hydraulic lifter and camshaft lubrication. Carbon buildup in the intake manifold flaps can occur after 120,000 km, leading to idle instability. Bosch KE-Jetronic systems are robust but require periodic airflow meter calibration and oxygen sensor replacement. Late-model units (2001+) feature OBD-II diagnostics. Timing chain wear is rare but inspection is advised beyond 180,000 km.
Oil Specs: Requires SAE 5W-40, API SL/CF specification (Mercedes SIB 01.0218). Modern equivalents acceptable with viscosity compliance.
Emissions: Euro 3 applies to 1999–2000 models (VCA Type Approval #VCA/EMS/8902). 2001–2003 models comply with Euro 4 under EU Directive 98/69/EC.
Power Ratings: Measured under DIN 70020 standards. Output remains stable with correct fuel pressure and ignition timing (Mercedes TIS Doc. A112600).
Mercedes-Benz Technical Information System (TIS): Docs A112600, SIB 01.0218
VCA Type Approval Database (VCA/EMS/8902)
ISO 1585:1976 Road vehicles — Engine test code — Net power
The Mercedes-Benz M 112.923 was used across Mercedes-Benz's W210 and W203 platforms with longitudinal mounting and rear-wheel drive. This engine received platform-specific adaptations-increased sound insulation in the W210 and revised intake manifolds in the W203-and from 2001 the introduction of updated engine management software for improved idle stability, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the right-side engine block near the exhaust manifold (Mercedes TIS A112600). The 6th and 7th digits of the VIN indicate engine type ('12' for M112 series). Pre-2001 models have silver intake manifolds with black actuators; post-2001 units feature revised actuator design with improved sealing. Critical differentiation from M112 variants: M 112.923 has KE-Jetronic injection and 10.0:1 compression; M 112.922 (lower output) used in export markets has different cam timing. Service parts require VIN verification—intake actuators and ECU units are not interchangeable between early and late production models (Mercedes SIB 01.0218).
The M 112.923's primary reliability risk is intake manifold flap actuator failure, with elevated incidence in high-mileage urban vehicles. Mercedes internal field reports from 2002 noted increased KE-Jetronic faults in vehicles with frequent short trips, while UK DVSA MoT data shows higher emissions failure rates in compact petrol models with airflow meter issues. Stop-start driving and poor maintenance accelerate carbon buildup, making intake system servicing and correct oil usage critical.
Analysis derived from Mercedes-Benz technical bulletins (1999-2003) and UK DVSA failure statistics (2000-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M112923.
Comprehensive technical documentation and regulatory references
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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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