Valve Gear, Servicing
Valve gear, servicing
Notes:
^ Cylinder heads which have cracks between valve seats or between valve seat inserts and the spark plug thread can be used further without reducing service life, provided cracks do not exceed a maximum of 0.3 mm in width, or when no more than first 4 turns of spark plug threads are cracked.
^ After installing camshafts, engine must not be started for approximately 30 minutes. Hydraulic valve compensation elements have to settle (otherwise valves will strike pistons).
^ After working on valve gear, turn engine carefully at least 2 rotations to ensure that none of the valves make contact when starter is operated.
^ Always replace gaskets and sealing rings.
1. 65 Nm
^ Use counterhold 3036 to loosen and tighten
2. Camshaft sprocket
^ For exhaust camshaft
^ Note installation position: Narrow web of camshaft sprocket must face toward front and marking for TDC No. 1 cylinder must be visible from front
3. Oil seal
^ For exhaust camshaft
^ Replacing, Refer to Seals an gaskets, Engine, Camshaft Oil Seal, Service and Repair.
4. Cylinder head
^ Checking valve guides, Refer to Valve Guide, Testing and Inspection
^ Refacing valve seats, Refer to Valve Seat, Service and Repair
^ Dowel sleeves for bearing caps must be located in cylinder head
^ Sealing transition points, Refer to Cylinder Head, Removing and Installing, Overview, See Fig. 3 and Fig. 4
5. Valve guide
^ Checking, Refer to Valve Guide, Testing and Inspection
6. Valve stem seal
^ Replacing, Refer to Seals and Gaskets, Engine, Valve Guide Seal, Service and Repair
7. Valve spring
^ Removing and installing, Refer to Seals and Gaskets, Engine, Valve Guide Seal, Service and Repair
8. Valve spring plate
9. Valve cotter
10. Hydraulic valve lifter
^ Checking, Refer to Lifter, Valve, Testing and Inspection
^ Removing and installing, Refer to Seals and Gaskets, Engine, Valve Guide Seal, Service and Repair
^ Do not interchange
^ Store with contact surface downward
^ Before installing check camshaft axial clearance, Refer to Camshaft, Engine, Testing and Inspection
^ Oil contact surface
11. Intake camshaft
^ Check radial clearance with Plastigage (valve lifters not installed):
^ Wear limit: 0.1 mm
^ Run-out: maximum 0.035 mm
^ Checking axial clearance, Refer to Camshaft, Engine, Testing and Inspection
^ Removing and installing camshafts, Refer to Camshaft, Engine, Service and Repair
12. Bearing cap for intake camshaft
^ Must be located on dowel sleeves
^ Dowel sleeves must be located in cylinder head
^ Note installation position
^ Installation sequence, Refer to Camshaft, Engine, Service and Repair
13. Double bearing cap
^ Must be located on dowel sleeves
^ Dowel sleeves must be located in cylinder head
^ Apply small amount of "AMV 188 001 02" to sealing surface before installation, Refer to Camshaft, Engine, Service and Repair
^ Sealing transition points between double bearing cap and cylinder head, Refer to Cylinder Head, Removing and Installing, Overview, See Fig. 3
14. Exhaust camshaft
^ Check radial clearance with Plastigage (valve lifters not installed):
^ Wear limit: 0.1 mm
^ Run-out: maximum 0.035 mm
^ Checking axial clearance, Refer to Camshaft, Engine, Testing and Inspection
^ Removing and installing camshafts, Refer to Camshaft, Engine, Service and Repair
15. Bearing cap for exhaust camshaft
^ Must be located on dowel sleeves
^ Dowel sleeves must be located in cylinder head
^ Note installation position
^ Installation sequence, Refer to Camshaft, Engine, Service and Repair
16. 10 Nm
17. 10 Nm
18. Drive chain
^ Check for wear
^ Mark position of chain before removing, Refer to Camshaft, Engine, Service and Repair
^ Removing and installing Removing and installing camshaft, Refer to Camshaft, Engine, Service and Repair
19. Camshaft adjuster
^ With camshaft adjustment valve -N205
^ Checking, Refer to Camshaft, Engine, Testing and Inspection
^ Secure with retainer for chain tensioner 3366 before removing
^ Removing and installing, Refer to Camshaft, Engine, Service and Repair
^ Sealing transition points between camshaft adjuster and cylinder head, Refer to Cylinder Head, Removing and Installing, Overview, See Fig. 4
20. Rubber/metal gasket
^ Apply sealant "AMV 188 001 022" before installation, Refer to Camshaft, Engine, Service and Repair
21. Gasket
^ Replace
22. Exhaust valve
^ With sodium filling
^ Note instructions on scrapping valves with sodium filling, Refer to Fig 1
^ Do not rework, only grinding is permitted
^ Valve dimensions, Refer to Fig 1
^ Checking valve guides, Refer to Valve Guide, Testing and Inspection
^ Refacing valve seats, Refer to Valve Seat, Service and Repair
23. Intake valve
^ Do not rework, only grinding is permitted
^ Valve dimensions, Refer to Fig . 1
^ Checking valve guides, Refer to Valve Guide, Testing and Inspection
^ Refacing valve seats, Refer to Valve Seat, Service and Repair
24. Oil seal
^ For intake camshaft
^ Replacing, Refer to Seals and Gaskets, Engine, Camshaft Oil Seal, Service and Repair
25. Hall sensor rotor ring
^ Note installation position: locate lug in notch on camshaft
26. Washer
^ Conical
^ Note installation position
27. 25 Nm
28. Housing for Hall sensor -G40
29. 10 Nm
Fig. 1 Valve dimensions
Note: Intake and exhaust valves must not be reworked Only grinding is permitted
WARNING:
^ Worn exhaust valves with sodium filling must not be scrapped in the usual way.
^ The valves must be cut into two pieces between shaft center and valve head using a metal saw. When doing this they must not come into contact with water. Throw a maximum of ten valves prepared in this way into a bucket of water. Then step backward because a sudden chemical reaction occurs during which the sodium filling is burnt.
^ The parts treated in this way can now be scrapped in the usual manner.