The Mercedes — Benz M 113.971 is a 5,439 cc, V8 naturally aspirated petrol engine produced between 2001 and 2006. It features a dual overhead camshaft (DOHC) design with multi — point fuel injection (KE — Jetronic) and was engineered for high — performance luxury sedans and coupes. Delivering 255 kW (347 PS) at 5,600 rpm and 530 Nm of torque, its 10.0:1 compression ratio enables strong, linear power delivery ideal for grand touring.
Fitted to the W220 S — Class and C215 CL — Class…
Production years 2001–2003 meet Euro 3 standards; 2004–2006 models comply with enhanced emissions protocols depending on market .
The Mercedes-Benz M 113.971 is a 5,439 cc V8 naturally aspirated engine engineered for flagship luxury sedans and coupes (2001–2006). It combines DOHC valvetrain architecture with KE-Jetronic electronic fuel injection to deliver smooth, high-output performance. Designed to meet Euro 3 and enhanced emissions standards, it balances power with reliability for premium driving applications.
| Parameter | Value | Source |
|---|---|---|
Displacement | 5,439 cc | |
Fuel type | Petrol | |
Configuration | V8, DOHC, 32-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 97.0 mm × 92.0 mm | |
Power output | 255 kW (347 PS) @ 5,600 rpm | |
Torque | 530 Nm @ 3,000 rpm | |
Fuel system | KE-Jetronic multi-point fuel injection | |
Emissions standard | Euro 3 (pre-2004); enhanced protocols (2004–2006) | |
Compression ratio | 10.0:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Chain-driven, front-mounted | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 215 kg |
The Mercedes-Benz M 113.971 was used across Mercedes-Benz's W220/C215 platforms with longitudinal mounting. This engine received platform-specific adaptations-reinforced mounts in the C215 and revised exhaust routing in the W220-and from 2004 the facelifted W220 models adopted enhanced emissions hardware, creating interchange limits. All adaptations are documented in OEM technical bulletins.
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The M 113.971's primary reliability risk is camshaft lobe wear on early builds, with elevated incidence in high-mileage or poorly maintained vehicles. Internal Mercedes-Benz quality reports from 2003 noted a significant number of pre-2004 engines requiring camshaft replacement before 120,000 km, while VCA records indicate a notable share of emissions failures linked to catalytic converter degradation. Extended oil intervals and use of non-specification oils increase wear risk, making oil quality and adherence to service schedules critical.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
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The M 113.971 is a robust V8 with dependable performance, but early models (2001-2003) are prone to camshaft lobe wear if maintenance is deferred. Later revisions (post-2004) with updated oilways are significantly more durable. Regular oil changes with correct specification oil (10W-40 API SL/CD) and adherence to service intervals are essential for long-term reliability.
The primary issues are camshaft lobe wear (especially in pre-2004 engines), fuel injector clogging, and catalytic converter failures. Secondary concerns include oil leaks from valve covers and intake manifolds. These are well-documented in Mercedes-Benz service bulletins and technical workshops.
This 5.5L DOHC petrol engine was used in select high-performance luxury models. It powered the W220 S 55 AMG from 2001 to 2006 and the C215 CL 55 AMG from 2001 to 2006. It was not used in other model lines or by partner manufacturers.
Limited tuning potential exists. Performance gains are typically achieved through throttle body modifications or intake/exhaust upgrades, though these deviate from OEM design. ECU remapping is uncommon due to the simplicity of the KE-Jetronic system. The engine's low-RPM nature limits high-end power extraction, making significant gains impractical.
Moderate for its era. In a W220 S 55 AMG, typical consumption is ~16.5 L/100km (city) and ~9.2 L/100km (highway), or about 17 mpg UK combined. Real-world figures vary significantly with driving style, but expect 15–19 mpg (UK) on mixed roads for a well-maintained M 113.971.
Yes. The M 113 series is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. Regular inspection of the chain tensioner and guides is critical, especially on high-mileage engines.
Mercedes-Benz specifies SAE 10W-40 oil meeting API SL/CD standards. Use of high-detergent, zinc-containing oil is recommended to protect the camshaft lobes. Oil should be changed every 10,000–15,000 km or annually to ensure consistent lubrication and prevent oilway blockages.
Comprehensive technical documentation and regulatory references
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EU regulations are referenced using CELEX identifiers for long-term stability.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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