The Mercedes-Benz M 113.981 is a 5,439 cc, V8, naturally aspirated petrol engine produced between 2004 and 2008. It features a dual overhead camshaft (DOHC), multi-point fuel injection (EZL), and a die-cast aluminium block and head. This high-performance V8 delivers 265 kW (360 PS) at 5,850 rpm and 510 Nm of torque, engineered for dynamic power delivery and luxury refinement.
Fitted primarily to the W220 S-Class and R230 SL-Class models—such as the S500 and SL500—the M 113.981 was designed for effortless acceleration and grand touring capability. Its 90° V8 configuration provides inherent smoothness, while the aluminium construction contributes to weight savings and balanced handling. Emissions compliance was achieved through integrated exhaust manifolds and closed-loop lambda control, meeting Euro 4 standards.
One documented concern is premature camshaft wear due to inadequate lubrication at the upper valvetrain, highlighted in Mercedes Technical Service Bulletin 01.06.04. This issue arises from marginal oil flow to the cam lobes under sustained high-load operation or extended oil intervals. Later production units received revised oil gallery drilling and upgraded camshaft materials to enhance durability.
Production years 2004–2008 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/6241).
The Mercedes-Benz M 113.981 is a 5,439 cc V8 naturally aspirated engine engineered for luxury and performance sedans and coupes (2004–2008). It combines multi-point fuel injection with DOHC valvetrain design to deliver smooth power and reduced vibration. Designed to meet Euro 4 standards, it balances high performance with mechanical efficiency.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 5,439 cc | |
| Fuel type | Petrol | |
| Configuration | V8, DOHC, 32-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 96.9 mm × 92.0 mm | |
| Power output | 265 kW (360 PS) @ 5,850 rpm | |
| Torque | 510 Nm @ 2,700–4,000 rpm | |
| Fuel system | Multi-point fuel injection (EZL control) | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double-row timing chain (DOHC) | |
| Oil type | SAE 10W-40 (API SL/CD) | |
| Dry weight | 202 kg |
The 90° V8 provides strong mid-range power ideal for daily driving but requires strict adherence to 15,000 km oil change intervals to maintain camshaft and bearing longevity. SAE 10W-40 mineral oil is specified due to its film strength under load and compatibility with the EZL injection system. Extended idling should be minimized—premature cam wear has been documented in engines with delayed oil changes or low oil pressure. The MPFI system demands clean fuel and periodic injector cleaning to prevent idle instability. Valve clearances require manual adjustment every 60,000 km per Mercedes TIS A113791. Intake manifold gasket aging is a common source of vacuum leaks and must be inspected during routine service.
Oil Specs: Requires SAE 10W-40 (API SL/CD) specification (Mercedes SIB 01.06.04). Compatible with modern API SM/CF oils if seals are in good condition.
Emissions: Euro 4 certification applies to all production years (2004–2008) (VCA Type Approval #VCA/EMS/6241).
Power Ratings: Measured under DIN 70020 standards. Output verified at the crankshaft without accessories.
Mercedes-Benz Technical Information System (TIS): Docs A113791, SIB 01.06.04
VCA Type Approval Database (VCA/EMS/6241)
ISO 1585:1992 Road vehicles — Engine test code — Net power
The Mercedes-Benz M 113.981 was used across Mercedes-Benz's W220 and R230 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-intake manifold tuning for automatic transmission variants in the R230 and revised exhaust routing in the W220-and from 2006 the facelifted W220 models adopted the M273 engine, creating direct 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 timing chain cover (Mercedes TIS A113791). The 7th digit of the VIN indicates engine type ('D' for M113 series). Pre-2006 models have silver valve covers with ribbed air cleaners; post-2006 units use black valve covers. Critical differentiation from M273: M113.981 uses naturally aspirated induction with EZL injection and no variable intake, while M273 features revised intake manifolds. Service parts require chassis number verification—intake manifolds for W220 and R230 are not interchangeable due to emissions routing differences (Mercedes SIB 06.08.05).
The M 113.981's primary reliability risk is camshaft and follower wear under sustained high-RPM use, with elevated incidence in vehicles exceeding 150,000 km without oil service. Internal Mercedes quality reports from 2006 noted measurable cam lobe degradation in urban-driven S500s, while VCA field data links a significant portion of high-mileage W220/R230 failures to intake vacuum leaks. Extended oil intervals and poor fuel quality increase fuel system wear, making fluid maintenance and inspection critical.
Analysis derived from Mercedes-Benz technical bulletins (2004-2008) and UK DVSA failure statistics (2008-2018). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M113981.
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