Details the procedure for measuring chain stretch using a specialized Mercedes timing gauge. It provides instructions for feeding a new chain through by crimping it to the old one, saving technicians from removing the entire front timing cover. Turbocharger Actuator Failure
Explains how to safely pull stuck injectors using slide hammers, clean the carbon without damaging the aluminum cylinder head, re-face the injector seat using a dedicated cutter tool, and install upgraded ceramic paste. Timing Chain Wear and Stretch
Introduced in 2006, this heavily updated version features a lower compression ratio, newer injectors, a faster turbocharger, and a diesel particulate filter (DPF). Core Mechanics Displacement: 2,148 cc (2.1 Liters) Bore and Stroke: 88.0 mm × 88.3 mm Firing Order: 1-3-4-2 Mercedes Workshop Manual Om646 Engine
At its core, the OM646 is a 2,148 cc (2.1-liter) engine with an 88 mm bore and 88.3 mm stroke. It features a dual-overhead-camshaft (DOHC) valvetrain driven by a robust double-row timing chain. The most notable upgrade was the adoption of a second-generation Bosch Common Rail Direct Injection (CDI) system. This system, which replaced the unit injector system of the OM611, operates at a maximum pressure of 1,600 bar, using 7-hole solenoid injectors for superior fuel atomization, resulting in smoother combustion, lower noise, and reduced emissions.
Rotate the crankshaft clockwise only using the 27mm harmonic balancer bolt. Details the procedure for measuring chain stretch using
Modern diesel troubleshooting requires precise sensor diagnostics. This section maps every critical sensor.
A typical OM646 workshop manual is a substantial document, often spanning over a thousand pages, and contains a wealth of specialized information, including: Timing Chain Wear and Stretch Introduced in 2006,
Exploded diagrams are often used in manuals to show parts like intake manifolds and mounting covers. Elring OM 646 Sprinter | PDF
The Mercedes-Benz OM646 engine is a legendary workhorse. Produced between 2002 and 2010, this 2.1-liter (2,148cc) inline-four cylinder diesel engine powered an entire generation of Mercedes vehicles, from the nimble and elegant E-Class (W211) to the indispensable Sprinter van.
The OM646 relies on high-pressure Bosch common-rail technology. This chapter covers the high-stakes fuel delivery system.
The Mercedes-Benz OM646 engine is a highly reliable inline-four diesel engine. It features a dual overhead camshaft (DOHC) layout and 16 valves. It utilizes common-rail direct injection (CDI) and a turbocharger. Mercedes used this powerplant extensively from 2002 through 2010. It appeared in the C-Class, E-Class, CLK, Vito, and Sprinter vans.