Camshaft, Lifters and Push Rods: Service and Repair

Assembly overview

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 threads of the spark plug threads are cracked.
^ After installing new hydraulic lifters the engine must not be started for approx. 30 minutes. (Valves will otherwise contact piston), then subsequently turn crankshaft two full turns.





1 - 100 Nm
^ Use counter support 3415 to loosen and tighten

2 - Camshaft pulley

3 - Seal

4 - Woodruff key
^ Check for secure seating

5 - 20 Nm

6 - Bearing cap
- Lightly coat bearing cap 1 contact surface with sealant D 454 300 A2

7 - Camshaft
^ Check radial clearance with Plastigage, Wear limit: 0.1 mm; Run-out: max. 0.05 mm

8 - Hydraulic lifter
^ Do not interchange
^ With hydraulic valve clearance compensation
^ Store with cam contact surface downward
^ Before installing check camshaft axial clearance.
^ Oil contact surfaces

9 - Keepers

10 - Valve spring upper retainer

11 - Valve spring

12 - Valve stem seal

13 - Valve guide
^ Service version with collar

14 - Cylinder head

15 - Valves
^ Do not rework. Only lapping-in is permitted
^ Valve dimensions.





Reworking cylinder head sealing surface

Cylinder head reworking limit:
- dimension - a - = at least 132.6 mm

Note:
^ If the sealing surface is being reworked then the valves must be set deeper by the same dimension (rework valve seat inserts), otherwise, the valves hit the pistons. When doing this, ensure that the minimum permissible dimension is attained. Valve seats, reworking





Checking camshaft axial clearance

Special tools, testers and auxiliary items required
^ Universal dial gauge bracket VW387
^ Dial gauge

Measure with hydraulic lifters removed and with first and last bearing caps installed.

Wear limit: max. 0.15 mm





Installation position of camshaft bearing caps

Note center offset. Before installing camshaft, fit bearing caps and determine installation position.





Valve dimensions

Note:
^ Valves must not be reworked. Only lapping-in is permitted.

Engine code AEG





Engine codes AVH, AZG, BDC, BEV, BGD