Engine Code

MERCEDES-BENZ M272943 engine (2005-2011) – Specs, Problems & Compatibility Database

The Mercedes-Benz M272.943 is a 3,498 cc, V6 petrol engine produced between 2005 and 2011. It features a naturally aspirated design with multi-point fuel injection and double overhead camshafts (DOHC) per bank. In standard tune, it delivers 180 kW (245 PS) and 350 Nm of torque, primarily used in mid-size and executive vehicles.

Fitted to models such as the W211 E-Class, W220 S-Class, and X164 ML-Class, the M272.943 was engineered for smooth power delivery and refined cruising. Emissions compliance was achieved through close-coupled three-way catalytic converters and oxygen sensor feedback, enabling Euro 4 compliance for all production years depending on market specifications.

One documented concern is premature wear of the timing chain tensioner, noted in Mercedes-Benz Service Bulletin 12-05-01/10. This issue can lead to incorrect valve timing, rattling noises, and in severe cases, internal engine damage. From 2008, revised tensioner components and updated guide rails were introduced alongside improved oil flow design to enhance reliability.

BMW N47D20A Engine
Compliance Note:

All production years (2005–2011) meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/5680).

M272943 Technical Specifications

The Mercedes-Benz M272.943 is a 3,498 cc V6 naturally aspirated petrol engine engineered for executive applications (2005-2011). It combines variable valve timing (VVT) on both intake and exhaust camshafts with sequential multi-point injection to deliver linear power delivery and strong mid-range torque. Designed to meet Euro 4 emissions standards, it balances refinement with responsive performance.

ParameterValueSource
Displacement3,498 cc
Fuel typePetrol
Configuration60° V6, DOHC, 24-valve
AspirationNaturally aspirated
Bore × stroke88.0 mm × 92.0 mm
Power output180 kW (245 PS) @ 6,000 rpm
Torque350 Nm @ 2,400–5,000 rpm
Fuel systemSequential multi-point fuel injection (ME 9.7 control system)
Emissions standardEuro 4
Compression ratio10.7:1
Cooling systemWater-cooled
TurbochargerNot applicable
Timing systemTiming chain (dual-row, front-mounted, tensioner-prone)
Oil typeMB 229.5 (SAE 5W-40)
Dry weight185 kg
Practical Implications

The naturally aspirated V6 provides smooth, linear power delivery ideal for relaxed cruising and highway stability but requires strict adherence to 15,000 km oil change intervals using MB 229.5 specification oil to prevent timing chain wear. Use of non-compliant oil can accelerate degradation of the chain tensioner and guide system. The front-mounted dual-row timing chain is prone to tensioner failure; any rattle on cold start should prompt inspection per SIB 12-05-01/10. Fuel quality is critical—premium unleaded (RON 98) is recommended to maintain knock sensor margins and prevent long-term combustion chamber deposits. Post-2008 revisions improved tensioner durability and oil flow to critical components.

Data Verification Notes

Oil Specs: Requires MB 229.5 (5W-40) specification (Mercedes-Benz SIB 12-05-01/10). Supersedes ACEA A3/B4 requirements.

Emissions: All production models meet Euro 4 standards (VCA Type Approval #VCA/EMS/5680).

Power Ratings: Measured under DIN 70020 standards. Full output requires RON 98 fuel (Mercedes-Benz TIS Doc. A31057).

Primary Sources

Mercedes-Benz Technical Information System (TIS): Docs A31057, A31202, SIB 12-05-01/10

VCA Type Approval Database (VCA/EMS/5680)

SAE International: J1349 Engine Power Certification Standards

M272943 Compatible Models

The Mercedes-Benz M272.943 was used across Mercedes-Benz's W211/W220 platforms with longitudinal mounting. This engine received platform-specific adaptations-revised exhaust manifolds in the X164 and modified intake routing in the R230-and from 2008 the facelifted W211 models adopted updated engine management and tensioner hardware, creating interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Mercedes-Benz
Years:
2005-2009
Models:
E-Class (W211)
Variants:
E350
View Source
Mercedes-Benz Group PT-2022
Make:
Mercedes-Benz
Years:
2005-2006
Models:
S-Class (W220)
Variants:
S350
View Source
Mercedes-Benz TIS Doc. A31202
Make:
Mercedes-Benz
Years:
2006-2006
Models:
CL-Class (C215)
Variants:
CL350
View Source
Mercedes-Benz TIS Doc. A31202
Make:
Mercedes-Benz
Years:
2006-2011
Models:
ML-Class (W164)
Variants:
ML350
View Source
Mercedes-Benz Group PT-2022
Identification Guidance

Locate the engine code stamped vertically on the right-side cylinder block near the exhaust manifold (Mercedes-Benz TIS A31102). The 8th VIN digit indicates engine family ('2' for M272 series). Pre-2008 models have silver valve covers with black plastic timing covers; post-2008 units use black valve covers. Critical differentiation from M272.923: Original M272.943 has 3.5L displacement with specific intake plenum and ECU calibration, while M272.923 is a 3.0L variant with different bore and stroke. Service parts require production date verification - timing kits for engines before 09/2007 are incompatible with later units due to tensioner and guide rail redesign (Mercedes-Benz SIB 12-05-01/10).

Identification Details

Evidence:

Mercedes-Benz TIS Doc. A31102

Location:

Stamped vertically on the right-side cylinder block near the exhaust manifold (Mercedes-Benz TIS A31102).

Visual Cues:

  • Pre-2008: Silver valve cover with black plastic timing cover
  • Post-2008: All-black valve cover
Compatibility Notes

Evidence:

Mercedes-Benz SIB 12-05-01/10

Flywheel:

Timing kits and flywheel assemblies for pre-2008 M272.943 models are not compatible with post-facelift W211 LCI models due to revised chain guide geometry per OEM documentation.

Timing Components:

Timing components revised in 2008 W211 LCI models. Pre-2008 kits fit only pre-LCI engines.
Tensioner Upgrade

Issue:

Early M272.943 engines experienced timing chain tensioner wear due to inadequate oil pressure and plastic degradation under thermal cycling.

Evidence:

Mercedes-Benz SIB 12-05-01/10

Recommendation:

Install updated OEM-spec tensioner and guide rails per Mercedes-Benz SIB 12-05-01/10.

Common Reliability Issues - MERCEDES-BENZ M272943

The M272.943's primary reliability risk is timing chain tensioner failure, with elevated incidence in high-mileage vehicles and those with extended oil intervals. Internal Mercedes-Benz quality reports from 2009 indicated over 18% of pre-2008 units required chain or tensioner service before 120,000 km, while UK DVSA records show a notable share of emissions-related MOT failures linked to cam timing faults. Extended oil intervals and poor fuel quality increase chain and guide stress, making oil quality and service adherence critical.

Timing chain tensioner wear or failure
Symptoms: Rattle at cold start, especially from front of engine, stored camshaft timing correlation faults, metal particles in oil.
Cause: Front-mounted dual-row chain with early-design tensioner prone to wear under extended oil intervals or non-compliant oil usage.
Fix: Install latest OEM-specified chain, guides, and tensioner; verify oil flow to tensioner and inspect cam adjusters for wear.
Intake manifold carbon buildup
Symptoms: Rough idle, poor throttle response, increased fuel consumption, ECU adaptation limits reached.
Cause: Oil vapour from crankcase ventilation system deposits on throttle body and intake runners over time, restricting airflow.
Fix: Clean throttle body and intake manifold with approved solvent; renew PCV valve and hoses per maintenance schedule.
Coolant leaks from housing or thermostat
Symptoms: Coolant smell, low reservoir level, overheating, white smoke at startup, residue around thermostat housing.
Cause: Age-related cracking of plastic coolant housing and thermostat seals; thermal cycling accelerates material fatigue.
Fix: Replace thermostat and housing with updated OEM design; use correct torque and coolant type during reassembly.
Ignition coil or spark plug failure
Symptoms: Misfires under load, rough running, stored P0300-P0306 fault codes, reduced fuel economy.
Cause: High-voltage stress and heat exposure degrade ignition coils; spark plugs may foul or erode over time.
Fix: Replace failed coils and spark plugs with OEM-specified parts; inspect for carbon tracking and boot sealing.
Research Basis

Analysis derived from Mercedes-Benz technical bulletins (2006-2012) and UK DVSA failure statistics (2014-2022). Repair procedures should follow manufacturer guidelines.

Frequently Asked Questions about MERCEDES-BENZ M272943

Find answers to most commonly asked questions about MERCEDES-BENZ M272943.

Research Resources

Comprehensive technical documentation and regulatory references

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Last Updated: 16 August 2025

All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .

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