Mercedes M256 3.0L Engine Specs, Problems, Reliability. The Mercedes-Benz M256, the most recent 3.0-liter inline six-cylinder gasoline engine, is a member of Mercedes modular engine family that consists of four-cylinder M260/M264 engines and OM656/OM654 diesels. The M256 3.0 L engine was first of all presented in the 2017 S-Class W222 S450 and S500 designs. The Mercedes hasn’t been producing inline-six engines for a very long time given that the last one – the M104, and now, this new 3.0-liter engine is slowly and efficiently changing the previous M276 V6 engine.
The M256 has a die-cast aluminum cylinder block. The cylinder walls are machined with a twin-wire-arc spraying technique (TWAS). This approach sprays a low-friction coating Nanoslide. Mercedes-Benz patented Nanoslide coating develops a microporous surface area of the cylinder walls and minimizes friction losses compared to conventional cast-iron cylinder liners. The cylinder-bore spacing is 90 mm – unified across the new household.
The engine has a forged-steel crankshaft and linking rods. The range in between the cylinder bore centers is 90 mm – an uniform size for the new family. The pistons are equipped with minimized piston rings and oil cooling ducts decreasing the temperature level of piston crowns.
Mercedes M256 3.0L Engine Specs, Problems, Reliability
The cylinder head for the M256 engine is produced from an aluminum-silicon alloy. There are two intake valves and 2 exhaust valves per each cylinder. For the very first time, Mercedes uses sodium-cooled, hollow flat-seat exhaust valves. Valves are activated by two overhead camshafts via roller camera followers. The consumption and exhaust camshafts are driven by a timing-chain situated on the flywheel side via the camshaft drive equipment. The timing chain also drives the high-pressure fuel pump and the oil pump.
The M256 cylinder head is equipped with M10 thread spark plugs for better cooling to be accomplished in the head. The M256 is likewise equipped with variable engine timing (for the intake and exhaust valves) and variable valve lift on the intake side (Mercedes-Benz CAMTRONIC). The change variety for the consumption camshaft has been increased to a 70 degrees crank angle. Like the most contemporary engines, the M256 is equipped with the high-pressure direct fuel injection system with extremely precise piezo injectors.
The M256 Mercedes-Benz engine includes the integrated starter-alternator (ISG) set up between the engine and automatic transmission. This choice became available, thanks to a 48V on-board electrical system. The ISG is strictly bolted to the crankshaft and exchanges energy between the driveshaft and the 48V lithium-ion battery with an energy material of nearly 1 kWh.
The 48V electrical system also supplies power to the electric water pump and cooling compressor. Air charging is the next crucial feature of the M256 engine. The M256 has a twin-scroll turbocharger with air gap-insulated exhaust manifold, plus an electric additional compressor (eZV) that is incorporated into the 48 volts electrical system. The electric auxiliary compressor removes the turbo lag result (it accelerates to 70,000 rpm within 300 ms).
Like M264 inline fours and M176 V8s, the M256 has a petrol/gasoline particulate filter (OPF), which works likewise to DPF in diesel vehicles. The engine satisfies Euro 6 Requirement 2.
Mercedes M256 Problems and Reliability
The M256 engines are still brand-new and do not have sufficient stats on common problems and failures. However it is worth bearing in mind that contemporary Mercedes engines are rather demanding on the quality of oils and fuels. Direct-injected engines are often prone to carbon deposits on consumption valves.
Mercedes M256 3.0L Engine Specs
|Cylinder block material||Cast Iron|
|Cylinder head material||Aluminum|
|Fuel system||Fuel Injection|
|Number of cylinders||4|
|Valves per cylinder||4|
|Type of internal combustion engine||Four-stroke, naturally aspirated and supercharged versions|
|Compression Ratio||8.5 (Kompressor); 9.6; 10.6|
|Torque, lb ft||136-140/3500-4000
|Engine oil weight||0W-30, 0W-40, 5W-30, 5W-40, 10W-40, 15W-40|
|Engine oil capacity, liter||5.5 (7.0 since 2000)|
|Oil change interval, mile||6,000|
|Applications||C 200 W202, C 200 Kompressor W202, C 200 Kompressor W203, CLK 200 C208, CLK 200 Kompressor C208, E 200/ 200 E W124,
E 200 W210, E 200 Kompressor W210, SLK 200 R170, SLK 200 Kompressor R170, V 200/ Vito 113 W638
Mercedes M256 3.0L Modifications
M256 E30 DEH LA R (lowered variation) – 362 hp (270 kW) at 5,500-6,100 rpm and 369 lb-ft (500 Nm) of torque at 1,600-4,000 rpm (output lacks ISA). Application: S-Class W222, CLS-Class C257, AMG GT, and GLE-Class V167.
M256 E30 DEH LA G (increased output variation) – 429 hp (320 kW) at 5,900-6,100 rpm and 384 lb-ft (520 Nm) of torque at 1,800-5,500 rpm (output is without ISA). Application: S-Class W222, CLS-Class C257, AMG GT, GLE-Class V167, and E-Class W213.