Mercedes Workshop Manual Om646 Engine | 2025 |

The Mercedes-Benz OM646 engine, a 2.1L turbocharged inline-four diesel, is widely regarded as one of the most robust engines the brand has ever produced, often reaching over 300,000 miles. Proper maintenance according to official workshop procedures is essential to maintaining this longevity. Workshop Overview & Manuals

1. Lock flywheel with tool (602 589 02 21 00).
2. Apply thread locking compound Loctite 2701 to new bolt.
3. Torque to 200 Nm.
4. Angle tighten an additional 90 degrees.
5. Wait 30 minutes before starting engine to allow locking compound to cure.

Injection: Common Rail Direct Injection (CDI) with Bosch solenoid or piezo injectors. Mercedes Workshop Manual Om646 Engine

Whether you are a Sprinter van owner hauling cargo or a C-Class owner seeking 500,000 miles, download the manual, buy the proper lock tools (you will need pin 602 589 00 21 00), and take your time. Your OM646 will thank you with another decade of smooth diesel torque. The Mercedes-Benz OM646 engine, a 2

• Consult the Manual: Always consult the workshop manual before starting a repair or maintenance task.
• Use the Right Tools: Use the right tools for the job to avoid damaging the engine or components.
• Take Your Time: Take your time and work methodically to avoid mistakes or oversights.

Piston and Crankshaft Specifications: Essential for full engine rebuilds. 2. Fuel System (CDI) Lock flywheel with tool (602 589 02 21 00)

Evolution: In 2006, the engine was updated (OM646 EVO) with a new turbocharger and ceramic glow plugs for better cold starts. 2. Common Maintenance: What Your Manual Will Highlight

Group 05 – Cylinder Head & Valve Train

• The critical procedure: Removing the camshaft bearing caps in a specific order to avoid breaking the camshaft.
• Checking valve clearance (hydraulic lifters).
• Resurfacing limits for the cylinder head (max distortion: 0.05mm).