Replacing the timing chains and setting the valve timing (V6) (Mercedes-Benz C-Class W203)

Special tools:

• Cover for fixing the camshaft - No.112589054000.
• Camshaft locking key - No.112589000100.
• Wrench for camshaft sprocket bolt - No.112589010300.
• Left camshaft locking device - No.112589013200.
• Right camshaft locking tool - No.112589003200.
• Crankshaft pulley locking device - No.112589004000.
• Flywheel locking device - No.112589034000.
• Timing chain link separator kit - No.602589024000.
• Timing chain link separator (element 1) - No.602589023300.
• Timing chain link separator (element 2) - No.602589056300.
• Timing chain link separator (element 3) - No.602589056301.
• Chain link joining tool - No.602589003900.
• Set of dies for joining chain links - No.103589016300.
• Tool box - No.602589009800.
• Devices for fixing the chain on the camshaft sprockets - No.112589044000.
• Viscous coupling pulley holder - No.113589004000.
• Viscous coupling locking key - No.113589000100.

General precautions

1. Disconnect the negative cable from the battery.

2. Remove the spark plugs to make it easier to turn the engine.

3. Unless otherwise stated, turn the engine in the normal direction.

4. Familiarize yourself with the requirements for tightening forces of threaded connections.

5. If equipped, mark the position of the CKP sensor before removing it.

6. Do not turn the crankshaft using the camshaft drive sprockets or devices.

7. Do not turn the crankshaft and camshaft with the timing chain removed.

Valve timing installation procedures

1. Bring the piston of the first cylinder [1] to the position 40° after TDC.

2. Make sure that the parallel grooves of both camshafts are correctly aligned with the cylinder head cut [2].

3. Install the locking devices [3] on the camshafts.

4. Check that the alignment marks on the balance shaft [4] are correctly positioned.

5. Before performing repair procedures, remove the tensioner assembly [5].

Note: When the piston of the first cylinder is set to the 40° after TDC position, the camshafts can be rotated without the risk of the valves contacting the piston crowns.

6. When assembling, bring the piston of the first cylinder to the position 40° after TDC and ensure that the copper-plated links of the chain are aligned with:

• Timing marks of the sprockets of both camshafts [6];
• With timing mark on balance shaft sprocket [7];
• With key and crankshaft timing mark [8].

Note: Once installation is complete, the copper plated chain links should be aligned every fourteenth turn.

Replacing the timing chain

1. Remove the right camshaft rocker arm shaft assembly with bearing caps;

2. Without tightening the fasteners, install the camshaft retaining cover [9] (tool no. 112589054000);

3. Install the chain locking devices on the camshaft sprockets (tool no. 112589044000);

4. Using the tools from the list above, connect the new chain to the old one on the right bank of cylinders - to put the chain on the sprockets, turn the crankshaft.

Note: Rocker Arm Shaft Assemblies Mounting Bolts (M7 x 84 mm) cannot be reused and must be replaced.

Removal of the balancing shaft is carried out in the following order:

1. Insert a suitable locking rod into the counterweight on the rear shaft journal [11];

2. Unscrew the mounting bolt and remove the counterweight;

3. Remove the balance shaft from the front side;

4. After completing the repair work, install the tensioner.

5. During assembly, do not forget to lubricate the central bolt of the crankshaft pulley.

Note: Do not block the flywheel/drive plate when removing/installing the crankshaft pulley bolt.