With a twin-cam setup, the timing chain installation is far more complex than on a single-cam engine. The manual details the procedure for locking the camshafts using locking pins and ensuring the timing chain tensioners are correctly set to prevent catastrophic engine failure.
The OM646 introduced significant advancements in fuel injection. The workshop manual demystifies this complex system: Mercedes Workshop Manual Om646 Engine
With the manual: You follow the "GF07.35-P-2000T" procedure. You turn the engine to 40° ATDC (after top dead center). You lock the crankshaft with tool (602 589 00 21 00). You loosen the camshaft sprockets. You break the old chain and pull the new one through. You reassemble and time it perfectly. With a twin-cam setup, the timing chain installation
When searching for a , you have three legitimate options: The workshop manual demystifies this complex system: With
The OM646 is heavily reliant on electronics. The manual transitions seamlessly from mechanical repair to software logic: