This diesel engine is turbocharged by a Variable Nozzle Turbine turbocharger (VNT or VGT - a variable geometry turbocharger) - Garrett GT2056VK. The high-pressure pump provides a maximum injection pressure of 1,600 bar (23,000 psi). The new piezo-injectors allow making up to 5 fuel injections per cycle. Injector nozzles have eight holes (previous engines had seven).

It features piezo-ceramics injectors instead of the previously used injectors with solenoid valves. The OM642 3.0L engine has the third generation of the common-rail direct injection system. This chain also drives the balancer shaft and the high-pressure fuel pump. The engine uses a double-bush (duplex) timing chain. Valves are actuated by camshafts via roller-type cam followers with hydraulic valve clearance compensation. On top of each cylinder bank, there is an aluminum cylinder head with four valves per cylinder (24 valves total) and intake and exhaust overhead camshafts (DOHC). The engine also has a balancing shaft which counter-rotates at the same speed as the crankshaft. The OM642 has a forged steel crankshaft which rotates in four bearings, forged steel lightweight connecting rods, and aluminum pistons with recesses in the piston crowns for the optimal combustion process.

Engine's aluminum crankcase weights only 41 kg. In 2014, the cylinder liners were replaced by the Mercedes-Benz's 'Nanoslide' cylinder wall coating. The new V6 CDI has an aluminum cylinder block with a 72-degree V angle which equipped with cast-in grey iron cylinder liners.

Bluetech mod