The Common Rail Diesel Injection system is sensitive. The manual outlines:
While the OM646 is known for a robust timing chain, the manual provides the exact "stretch" tolerances and replacement steps. Mercedes Workshop Manual Om646 Engine
Guidelines on how to remove them without snapping them in the cylinder head. Why You Need a Dedicated Manual The Common Rail Diesel Injection system is sensitive
Including oil feed line checks.
Specifications for MB 229.31 or 229.51 oil grades. Mercedes Workshop Manual Om646 Engine
Most versions featured a VNT turbocharger to reduce lag and improve torque across the rev range.
Before diving into the manual, it is important to understand what makes the OM646 unique. It succeeded the OM611 and introduced several refinements: