Cylinder Head Assembly

Valve Gear, Servicing


Note:
- Cylinder heads which have cracks between the valve seats or between valve seat inserts and the spark plug thread can be used further without reducing service life, the cracks do not exceed a maximum of 0.3 mm in width, or when no more than the first 4 turns of the spark plug threads are cracked.

- After installing new lifters the engine must not be started for about 30 minutes (otherwise valves will strike pistons). Turn crankshaft two complete revolutions before starting.

- Carefully apply a small amount of sealant D 454 300 A2 at the four end points of the sealing surfaces on the cylinder head, using a small screwdriver.







1 - Double bearing cap
- Lightly coat with sealant 454 300 A2 before installing

2 - Exhaust camshaft bearing cap
- With connection for oil feed line
- Watch position of dowel sleeve
- Note installation position and numbering
- Lightly coat last bearing cap (after the chain) with sealant D 454 300 A2 before installing

3 - 10 Nm

4 - Oil line outlet side
- For lubricating bearing cap
- Note installation position

5 - Exhaust camshaft
- Checking axial clearance
- Removing and installing
- Check radial clearance with Plastigage (litters removed) Wear limit: 0.1 mm Run- out: 0.01 mm (maximum)

6 - Cap
- Always replace

7 - Oil line, inlet side
- Note installation position
- For lubricating bearing cap

8 - Inlet camshaft bearing cap
- With connection for oil feed line
- Note installation position and numbering

9 - Inlet camshaft
- Checking axial clearance
- Removing and installing
- Check radial clearance with Plastigage (lifters removed) Wear limit: 0.1 mm Runout: 0.01 mm (maximum)

10 - Drive chain
- Installing

11 - 10 Nm

12 - Mechanical camshaft adjuster
- With camshaft adjustment valve -N205-
- Secure with special tool 3366 before removing

13 - Hydraulic lifter
- Removing and installing with cylinder head installed

14 - Valve cotters

15 - Valve spring plate

16 - Valve spring

17 - Valve stem seal
- Replacing with cylinder head installed

18 - Rubber/metal gasket
- Always replace

19 - Seal
- Always replace

20 - Cylinder head
- Checking for distortion
- Reworking

21 - Exhaust valve

22 - Inlet valve

23 - Oil seal (Hall sensor end)
- Always replace

24 - Rotor for Hall sensor
- Note position (notch on camshaft)

25 - Washer
- Conical

26 - 25 Nm

27 - Hall sensor

28 - 10 Nm

29 - 30 Nm +180° (1/2 turn)

30 - Camshaft sprocket

31 - Oil seal (toothed belt end)
- Replacing







Sealing end points of joints between bearing caps and cylinder head

- Carefully apply small quantity of sealant D 454 300 A2 at four end points of sealing surfaces on cylinder head -arrows-, using a small screwdriver.