Remove the oil filter cap from the top engine bay using a 32mm socket.
18.0:1 (Early variants) or 17.5:1 (EVO variants) Mercedes Workshop Manual Om646 Engine
Disconnect the battery and drain the cooling system completely. Remove the oil filter cap from the top
Mercedes relies heavily on external and internal Torx fasteners across the entire engine block. The Mercedes OM646 engine stands as a testament
The Mercedes OM646 engine stands as a testament to robust, straightforward diesel engineering. It offers excellent fuel economy and longevity that rivals many modern engines, but it demands respect for its specific maintenance needs. Whether you are a professional technician or a dedicated DIYer, securing the correct Mercedes Workshop Manual for your specific OM646 engine code is not just a recommendation—it is a fundamental part of ownership. Using the manual to follow precise torque sequences, diagnostic procedures, and service schedules will ensure that your OM646 delivers hundreds of thousands of miles of reliable service.
Oil in coolant, coolant loss, or external oil seepage. The manual’s procedure: Intake manifold removal, fuel lines disconnection, and meticulous cleaning. The manual lists the seal part numbers and the order to tighten the cooler housing bolts to prevent distortion.