Cylinder Head Assembly: Service and Repair

Cylinder Head, Removing and Installing






Compression, checking refer to Compression Check.

Notes:
^ When installing an exchange cylinder head complete with camshaft, the contact surfaces between the hydraulic lifters and the cam lobes must be oiled before installing the valve cover.
^ The plastic protection pieces for the open valves must not be removed until immediately before installing cylinder head.
^ If cylinder head is replaced, all coolant in system must also be replaced.

1. Expanding clip
2. Toothed belt guard - upper section
3. Toothed belt
^ Mark direction of engine rotation before removing
^ Check for wear
^ Do not kink
^ Removing, installing, tensioning refer to Timing Components; Timing Belt.
4. 45 Nm (33 ft. lbs.)
5. Camshaft sprocket
^ Drive off camshaft taper using hammer and drift through toothed belt guard openings
6. 10 Nm (7 ft. lbs.)
7. Toothed belt guard, rear
8. Valve cover
9. Cap
^ Replace seal if damaged
10. Sealing washer, upper
^ Replace if damaged
11. Dished washer
12. Cap
13. To intake hose
14. Retaining clip
15. Positive Crankcase Ventilation valve
^ For crankcase breather
16. Gasket
^ Replace if damaged
17. Valve cover gasket
^ Replace if damaged
^ Insert projections into holes on cylinder head
18. Crankcase breather
19. Cylinder head bolt
^ Replace
^ Note sequence when loosening and tightening refer to Cylinder Head, Installing.
20. Mounting clip
21. 0-ring
^ Replace
22. Lower sealing cone
23. injector lines
^ Tighten to 25 Nm (18 ft. lbs.)
^ Remove with 3035
^ Always remove fuel lines as a complete assembly
^ Do not alter shape
24. Cylinder head
^ Check for distortion refer to Fig. 1
^ installing
^ If replaced,also replace complete engine coolant
25. Fuel injector
^ Removing and installing refer to Powertrain Management; Fuel Delivery and Air Induction.
26. Glow plug
^ 15 Nm (10 ft. lbs.)
^ Check
27. Lifting eye
28. Cylinder head gasket
^ Replace
^ Note marking refer to Fig. 2
^ If replaced,also replace complete engine coolant
29. 20 Nm (15 ft. lbs.)
30. idler roller
31. 25 Nm (18 ft. lbs.)
32. Tensioning roller
^ Checking semi-automatic toothed belt tensioning roller refer to Timing Components; Timing Belt.
33. Eccentric
^ For tensioning roller
34. 20 Nm (15 ft. lbs.)





Fig. 1 Cylinder head distortion, checking
^ Max. permissible distortion: 0.1 mm

Note: Reworking Diesel cylinder heads is not permissible.





Fig. 2 Cylinder head gasket, identification
^ Part No. = black arrow
^ Holes/notches = white arrow

Note: Different thickness cylinder head gaskets are installed depending on the piston crown projection. When replacing the head gasket, ensure the replacement gasket has the same identification as the one that was removed.




Cylinder Head, Installing





Special tools, workshop equipment, test and measuring appliances and aux. items required
^ 3070 Guide pin
^ VAG 1306 Drip tray
^ VAG 1332 torque wrench 40 to 200 Nm (30 to 148 ft. lbs.)

Installing

Notes:
^ Always replace cylinder head bolts.
^ In cases of repair carefully remove gasket remains from cylinder head and cylinder block. Ensure that no long grooves or scratches are created. When using abrasive paper do not use a coarser grade than 100 (for example, do not use Grade 80).
^ Carefully remove all emery and abrasive remains.
^ Remove new cylinder head gasket from packaging, just before installation.
^ Handle gasket extremely carefully. Damaging the silicone layer or the indented area will lead to leaks.
- Turn crankshaft to TDC marking before installing cylinder head.
- Turn crankshaft against engine direction of rotation until all pistons are approximately equally placed below TDC.
- Install cylinder head gasket.





- To centralize, screw guide pins from 3070 into the outer threaded holes on the intake side.
- Fit cylinder head, screw in 8 remaining cylinder head bolts and tighten by hand.
- Remove guide pins with 3070 removal tool and install cylinder head bolts.





- Tighten cylinder head in four stages in sequence shown as follows:
1. Tighten initially with torque wrench:
Stage I = 40 Nm (30 ft. lbs.)
Stage II = 60 Nm (44 ft. lbs.)
2. Turn further with normal wrench:
Stage III = 1/4 turn (90°
Stage IV = 1/4 turn (90°)

Notes:
^ Loosening cylinder head: Reverse sequence.
^ Re-torquing cylinder head after repairs is not necessary
- After tightening the cylinder head, turn camshaft so cam lobes for cyl. 1 point evenly upwards. Turn crankshaft, in direction of engine rotation, to TDC before installing toothed belt.