Valve gear, servicing: Notes
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, provided 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. See SEALING END POINTS OF JOINTS BETWEEN BEARING CAPS AND CYLINDER HEAD .
NOTE:
The following list refers to items in Fig 1.
- Double bearing cap
- Lightly coat with sealant 454 300 A2 before installing. See INSTALLING .
- Exhaust camshaft bearing cap
- With connection for oil feed line
- Watch position of dowel sleeve
- Note installation position and numbering. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- Lightly coat last bearing cap (after the chain) with sealant D454 300 A2 before installing
- 10 Nm
- Exhaust camshaft
- Checking axial clearance. See CAMSHAFT AXIAL CLEARANCE, CHECKING
- Removing and installing. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- Check radial clearance with in Plastigage™ (lifters removed) Wear limit: 0.1 mm Runout: 0.01 mm (maximum)
- Cap
- Always replace
- Inlet camshaft bearing cap
- With connection for oil feed line
- Note installation position and numbering. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- Inlet camshaft
- Checking axial clearance. See CAMSHAFT AXIAL CLEARANCE, CHECKING .
- Removing and installing. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- Check radial clearance with Plastigage™ (lifters removed)
Wear limit: 0.1 mm
Run-out: 0.01 mm (maximum)
- Drive chain
- Installing. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- 10 Nm
- Mechanical camshaft adjuster
- With camshaft adjustment valve -N205
- Secure with special tool 3366 before removing. See CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING .
- Hydraulic bucket lifter
- Notes, see HYDRAULIC VALVE LIFTERS, CHECKING
- Removing and installing with cylinder head installed, see CAMSHAFTS AND CAMSHAFT ADJUSTERS, REMOVING AND INSTALLING
- Valve keepers
- Valve spring plate
- Valve spring
- Valve stem seal
- Replacing with cylinder head installed, see VALVE STEM SEALS, REPLACING
- Rubber/metal gasket
- Always replace
- Seal
- Always replace
- Cylinder head
- Checking for distortion, see CYLINDER HEAD, CHECKING FOR DISTORTION
- Reworking, see CYLINDER HEAD, REWORKING
- Exhaust valve
- Inlet valve
- Oil seal (Hall sensor end)
- Always replace. See OIL SEALS IN CYLINDER HEADS, REPLACING .
- Rotor for Hall sensor
- Note position (notch on camshaft)
- Washer
- Conical
- 25 Nm
- Hall sensor
- 10 Nm
- 30 Nm +180° (1/2 turn)
- Camshaft sprocket
- Oil seal (toothed belt end)
- Replacing, see OIL SEALS IN CYLINDER HEADS, REPLACING