The Mercedes-Benz M272 engine is a 90° V6 gasoline engine introduced in 2004 as a successor to the M112. A parts diagram of this engine typically highlights its modular DOHC design, featuring four valves per cylinder and continuous variable valve timing (VVT) for both intake and exhaust camshafts. Key Components in an M272 Parts Diagram
Cylinder Head and Valvetrain: The diagram shows a DOHC setup with 4 overhead camshafts. Key parts include the 4 Camshaft Adjusters (vane-type, oil-pressure controlled) and 4 Camshaft Position Sensors (Hall effect).
Intake System: A prominent feature is the Magnesium Intake Manifold, which includes variable-length intake runners and integrated swirl/tumble flaps to optimize air mixture at different RPMs. The Throttle Valve Actuator and Mass Air Flow (MAF) Sensor are typically shown positioned behind this assembly.
Engine Block and Internals: The block is cast aluminum with a 90° V-angle and silicon/aluminum-lined cylinders. Internal components include a Counter-rotating Balance Shaft, iron-coated aluminum pistons, and forged steel connecting rods.
Timing System: The timing chain diagram illustrates the routing of the chain over the crankshaft gear, balance shaft gear, and intake camshaft gears. It also includes the Step-type Chain Tensioner, which must be manually reset if removed.
Auxiliary Systems: These include the Oil Filter Housing, Coolant Thermostat, and the Poly-V Belt with its associated tensioner and idlers.
The most striking visual difference between the M112 and the M272 is the cylinder head design. While the M112 used three valves per cylinder (two intake, one exhaust), the M272 went back to a 4-valve per cylinder setup (Double Overhead Camshaft, or DOHC).
The Mercedes-Benz M272 is a naturally aspirated 90° V6 engine that introduced several advanced features, including continuous variable valve timing (VVT) and a variable-length intake manifold. A parts diagram for this engine typically highlights three primary areas: the valvetrain and timing system, the variable intake manifold, and the engine block assembly. Key Engine Components and Systems
Technical diagrams like those found on Benzbits often break down the engine into these essential sections:
Valvetrain & Timing: The M272 uses a Dual Overhead Cam (DOHC) design with four valves per cylinder. Diagrams show four camshaft adjusters (vane-type, oil-controlled) and four Hall-effect camshaft position sensors. A critical component in these diagrams is the balance shaft, located between the cylinder banks to counteract vibrations. Mercedes Benz M272 Engine Parts Diagram
Intake Manifold Assembly: This magnesium manifold is a common focus for repair diagrams due to its "tumble flaps" and "swirl flaps" which optimize airflow for different RPM ranges. Key parts include the switchover diaphragm and the actuator arms, which are known to be wear points.
Engine Block & Mechanicals: The diagram illustrates the aluminum block with silicon/aluminum lined cylinders, a lightweight one-piece crankshaft, and iron-coated aluminum pistons. The chain tensioner, located at the lower right front of the engine, is a step-type component that must be manually reset if removed.
Thermostat & Cooling: Unlike its predecessor, the M272 features an electrically assisted thermostat managed by the engine control unit (ME 9.7) to improve warm-up times and temperature regulation. Critical Maintenance Visuals Repair-focused diagrams often include:
Timing Alignment Marks: These indicate the crankshaft's 40° After Top Dead Center (ATDC) position, which is used for checking the basic timing of the camshafts and the balance shaft.
Serpentine Belt Routing: Detailed diagrams for the accessory belt system are essential for replacing the belt, tensioner, and pulleys.
Understanding the Mercedes-Benz M272 Engine: A Complete Parts Diagram Guide
The Mercedes-Benz M272 V6 engine is one of the most common powerplants found in the silver star’s lineup from the mid-2000s to the early 2010s. Known for its smooth power delivery and versatility, it powered everything from the C-Class to the flagship S-Class.
However, as these engines age, maintaining them requires a clear understanding of their complex architecture. This guide breaks down the M272 engine parts diagram into digestible sections to help you identify components for repair or performance upgrades. 1. The Core Block and Rotating Assembly
At the heart of the M272 is a 90-degree aluminum engine block with silicon/aluminum lined cylinders. The Mercedes-Benz M272 engine is a 90° V6
Cylinder Heads: Twin-cam (DOHC) design with four valves per cylinder.
Pistons & Connecting Rods: Forged steel connecting rods and aluminum alloy pistons.
Crankshaft: A forged steel unit with four main bearings. Note that because of the 90-degree V-angle, a balance shaft is located in the "vee" of the engine to counteract vibrations—a critical part often referenced in early M272 diagrams due to high failure rates of the sprocket. 2. The Valvetrain and Timing System
The M272 uses a sophisticated timing system to optimize efficiency across the RPM range.
Timing Chain: A double-row roller chain that connects the crankshaft to the camshafts.
Camshaft Adjusters (Phasers): Located at the front of each camshaft, these allow for independent variable valve timing (VVT) on both intake and exhaust sides.
Camshaft Position Sensors: Four sensors (one for each cam) that report data back to the ECU. These are common leak points for oil.
Solenoids (Magnets): These actuate the camshaft adjusters. Updated "Gold" connectors are often seen in diagrams as the recommended replacement for older, leaking units. 3. Intake and Fuel System
The M272 is famous for its Tumble Flap system within the intake manifold. Example legend (short)
Intake Manifold: A magnesium alloy unit featuring long and short runners.
Variable Intake Flaps: These flaps change the airflow path based on engine load. In many diagrams, you will see the "triangular" plastic lever on the front of the manifold—this is a frequent failure point where the plastic snaps, requiring a metal replacement kit.
Fuel Rail and Injectors: Sequential multi-port fuel injection (except for the rare CGI direct-injection variants). 4. Cooling and Lubrication Keeping the all-aluminum M272 cool is vital for longevity.
Water Pump: Belt-driven and located at the front-center of the engine.
Thermostat Housing: An electronically controlled unit that allows the engine to reach operating temperature faster.
Oil Filter Housing: Mounted on the top-front of the engine for easy access. It often shares a gasket with the Oil Cooler, which is a common site for external oil leaks. 5. Ignition and Electrical Coil Packs: Six individual "coil-on-plug" units.
Spark Plugs: Located deep within the cylinder head, requiring a thin-walled socket for removal.
ECU (Bosch ME 9.7): Typically mounted directly on top of the intake manifold, where it stays cool via airflow but is susceptible to heat soak over many years. Common Search Terms for Locating Specific Diagrams
When looking for official Mercedes Star Diagnostic (SDS) or EPC (Electronic Parts Catalog) diagrams, use these specific sub-group terms: Group 01: Engine Housing (Crankcase and Cylinder Heads) Group 05: Valvetrain (Camshafts and Timing Chain) Group 14: Intake Manifold and Air Ducts
Group 15: Electrical Equipment (Starter, Alternator, Ignition) Summary for DIYers
If you are using a parts diagram to perform a repair, always verify your VIN. The M272 underwent several revisions, most notably the "Balance Shaft Gear" update. Engines with serial numbers higher than 2729xx 30 468993 generally have the updated, hardened gear that does not suffer from premature wear.