Caution! Risk of damage to valves and piston crowns after working on the valve train. Since the hydraulic lifters must be settled, after installing the camshafts the engine should not be run for approx. 30 min. To ensure that no valves are in contact with the cylinder head during operation, carefully rotate the engine at least 2 revolutions. Cylinder heads with cracks between the valve seats or between the valve seat ring and the spark plug seat threads can be used without reducing service life, provided the cracks are small, no wider than 0.3 mm, or if they affect only the first 4 threads of the spark plug seat threads.
The figure shows the cylinder head of cylinder bank 2 (left).
1. Plug: Install with sealant. 2. Cylinder head. 3. Oil seal. 4. Valve spring. 5. Hydraulic compensator: fixed in the roller lever "pos. 8"; mark mont. reinstallation position: lubricate the working surfaces before installation. 6. Valve spring plate. 7. Valve cracker. 8. Rocker arm: mark installation. reinstallation position: Check the roller bearing for ease of movement: Lubricate the working surfaces before installation; for installation, secure with the safety clamp "pos. 9" on the hydraulic compensator "pos. 5". 9. Locking clamp: not supplied separately, check the reliability of the fastening. 10. Intake camshaft; maximum runout: 0.04 mm. 11. Bolt: replace. 12. Camshaft frame: with integrated camshaft bearings. 13/14. Rectangular section ring. 15. Exhaust camshaft; maximum runout: 0.04 mm. 16. Mesh oil filter. 17. Inlet valve: cannot be machined, only lapping is allowed; mark mont. reinstallation position. 18. Exhaust valve: cannot be machined, only lapping is allowed; mark mont. reinstallation position.
Mounting position of the valve spring
The frequent turns of the "arrow" spring face the cylinder head.
Camshaft frame - last and tightening torque
The camshaft frame for the left cylinder head is shown. On the right cylinder head, the steps are performed in a mirror image. Bolts tightened at the tightening angle should be replaced. Tighten the bolts in 3 stages in the sequence shown.
| Step | Bolts | Tightening torque/rotation angle |
| 1 | "1...21" | Tighten the bolts by hand until they stop The frame must fit snugly against the cylinder head over the entire mating surface |
| 2 | "1...21" | 8 Nm |
| 3 | "1...21" | Turn 90° further |
Removal and installation camshafts
Remove the chains from the camshafts. To remove the camshafts from the left cylinder head, remove the vacuum pump. To remove the camshafts from the right cylinder head, remove the high-pressure pump and the high-pressure pump drive housing. Unscrew the "arrow" bolt and remove the system valve. regulation of the timing phases.
Disconnect connector "1" on the Hall sensor. Ignore the "arrow.". Loosen the camshaft frame bolts in sequence. "21...1". For the right camshaft frame, the steps are performed in mirror order. Remove the bolts, carefully remove the glued camshaft frame and place it on a soft pad on the workbench.
Remove the camshaft retainer "T40133" "arrows". Mark and remove the camshafts.
Install
Replace gaskets and plugs. Crankshaft "1" is locked in the "TDC" position using the "T40069" locking screw. The hydraulic lifters and rocker arms are installed.
Remove any remaining sealant from the cylinder head and camshaft frame, for example, with a rotating brush attachment with plastic bristles. Clean the sealing surfaces from oil and grease. Check the "arrow" mesh for contamination and clean it if necessary. Lubricate the working surface of the camshafts with oil.
Place the camshafts into the frame. The camshafts must lie precisely in the axial bearings of the frame's "arrows." The joints of the rectangular rings "1, 2, 3" must be facing up or down. The joints of rectangular cross-section rings must not under any circumstances be facing sideways. Rotate the camshaft frame with the camshafts inserted, while holding the camshafts in the frame.
Turn the camshafts until the threaded holes with the arrows facing upwards. Check that the camshafts are positioned correctly in the frame axle bearings.
Install the camshaft retainers "T40133" on both cylinder heads and tighten to 25 Nm "arrows". Observe the sealant shelf life. Cut off the tube tip along the front mark (opening diameter approx. 2 mm). Turn the camshaft frame again. Danger of contamination of system channels. lubrication when there is excess sealant. The sealant beads must not be thicker than the specified size. Apply a bead of sealant "4...8" to the clean seating surfaces of the camshaft frame, as shown in the figure. Sealant bead thickness: 2.0 mm. Apply a bead of sealant "1...3" to the clean camshaft frame mounting surfaces, as shown in the figure. Sealant bead thickness: 2.5 mm. Install the camshaft frame within 5 minutes after applying the sealant.
Place the camshaft frame on the cylinder head. Insert the "T40116" retaining pins into the frame and cylinder head.
Tighten the camshaft frame mounting bolts. After installing the crankshaft frame, allow the sealant to cure for about 30 minutes. Clean the cylinder head plug hole of oil and grease. Apply sealant around the outer perimeter of the arrowhead plug. Install the plug flush.
Remove the "T40116" retaining pins with the "T10133/3" slide hammer.
Installation in reverse order. Install the high pressure pump and the high pressure pump drive housing. Install a vacuum pump. Install the drive chains on the camshafts. Risk of damage to valves and piston crowns after working with the valve mechanism. Since the hydraulic lifters must be settled, after installing the camshafts the engine should not be started for approx. 30 min. To ensure that no valves come into contact with the cylinder head during operation, carefully crank the engine at least 2 revolutions.
