Contents: Removal ↡ Installation ↡
Removal
1. Remove the top engine covers, refer to the relevant section.
2. Remove the injectors, refer to Section Removal and installation injectors.
3. Remove the cylinder head cover, refer to the relevant section.
4. Set the piston of the first cylinder to the TDC position.
5. Secure the intake camshaft by inserting the locking pin (1) through the first camshaft bearing cap into the hole in the intake camshaft sprocket (2).
6. Remove the chain tensioner, refer to the relevant section.
7. Remove the front cover, refer to the relevant section.
8. Remove the upper slide guide, refer to the relevant section.
9. Mark the camshaft sprocket in relation to the chain.
Note: If the camshaft should not rotate during subsequent work, connect the sprocket and chain with a cable connector.
10. Disconnect the sprocket from the exhaust camshaft and remove it. Remember the guide pins. Remove the sprocket together with the chain.
11. Engine 611: Remove the camshaft bearing caps:
- Unscrew the bolts securing the E1, E3, E5, as well as A1, A3 and A5 covers. In doing so, pay attention to the markings on the covers for subsequent installation.
- Loosen the bearing cap mounting bolts E2, E4 and A2, A4 in several steps, one turn each time, to relieve the camshaft backpressure. Make sure that the camshafts do not warp when unscrewing the bolts. Unscrew the bolts completely and remove the caps.
12. Engine 612: Remove the camshaft bearing caps as follows:
- Unscrew the bolts securing the E1, E3, E4, E6, as well as A1, A3, A4 and A6 covers. In doing so, pay attention to the markings on the covers for subsequent installation.
- Loosen the bearing cap mounting bolts E2, E5 and A2, A5 in several steps, one turn each time, to relieve the camshaft backpressure. Make sure that the camshafts do not warp when unscrewing the bolts. Unscrew the bolts completely and remove the caps.
13. Remove the intake and exhaust camshafts.
Installation
1. Lubricate the tappet and camshaft bearing journals with clean engine oil. Check the ease of movement of the tappets.
2. Install the intake and exhaust camshafts and align them with the axial bearing. Pay attention to the location of the shafts. The shaft markings are applied at the point of contact with the thrust bearing.
- 01 Intake camshaft.
- 00 Exhaust camshaft.
3. Install the camshafts so that the holes (3) in the camshaft sprockets are opposite each other and the markings on the camshaft and bearing cap match.
Caution! The camshafts are very sensitive to overvoltage and can be damaged. Therefore, make sure that the installation does not lead to any overload of the shafts.
4. Turn the crankshaft in the opposite direction until the piston position of the first cylinder is 30° before TDC.
5. Install the bearing caps according to their markings.
Caution! The bearing caps are asymmetrical. Make sure that they are not displaced.
6. Engine 611: Secure the camshaft bearing caps as follows:
- Tighten the bolts securing the E2, E4 covers; and A2, A4 in several stages, each time one turn. Tighten the covers with a torque of 9 Nm. Make sure that the camshafts are not warped when tightening the bolts.
- Tighten the bearing caps E1, E2, E5, as well as A1, A3, A5 to a torque of 9 Nm.
7. Engine 612: Secure the camshaft bearing caps as follows:
- Tighten the bolts securing the E2, E5 covers; and A2, A5 in several stages, each time one turn. Tighten the covers with a torque of 9 Nm. Make sure that the camshafts are not warped when tightening the bolts.
- Tighten the bearing caps E1, E3, E4, E6 and A1, A3, A4, A6 to a torque of 9 Nm.
8. Set the piston of the first cylinder to the TDC position.
9. Secure the intake camshaft by inserting the locking pin through the first bearing cap into the hole in the intake camshaft sprocket.
10. Install the sprocket with the chain on the intake camshaft, paying attention to the guide pin.
11. Secure the sprocket with new bolts to a torque of 18 Nm. If necessary, cut and remove the cable connector.
12. Install the top guide, refer to the relevant section.
13. Install the chain tensioner with a new sealing ring, refer to the relevant section.
17. Install the upper engine covers, refer to the relevant section.