A3 Mk2
| Valve gear - exploded view of components |
| 1 - | Cylinder head |
| q | Machining valve seats → Chapter |
| 2 - | Bearing shell |
| q | Note installation position |
| q | Do not interchange used bearing shells (mark positions) |
| q | Make sure that the retaining lugs are correctly seated in the bearing caps and the cylinder head |
| q | Fit new bearing shells if camshaft is being renewed. |
| 3 - | Camshaft |
| q | Check radial clearance with Plastigage |
| q | Radial clearance: wear limit: 0.11 mm |
| q | Runout: max. 0.04 mm |
| q | Checking axial clearance → Chapter |
| q | Removing and installing → Chapter |
| 4 - | Bearing shell |
| q | Note installation position |
| q | Do not interchange used bearing shells (mark positions) |
| q | Make sure that the retaining lugs are correctly seated in the bearing caps and the cylinder head |
| q | Fit new bearing shells if camshaft is being renewed. |
| 5 - | Bearing cap |
| q | Installation sequence → Chapter „Removing and installing camshaft“ |
| q | Apply sealant to bearing caps 1 and 5 → Fig. |
Caution
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| 6 - | 8 Nm + 90° (1/4 turn) further |
| q | Renew |
| 7 - | 20 Nm + 90° (1/4 turn) further |
| q | Renew |
| q | Note correct sequence for loosening and tightening → Chapter „Removing and installing camshaft“ |
| 8 - | Rocker arm shaft |
| q | Mark allocation of rocker arms |
| q | Do not interchange |
| q | Removing and installing → Chapter „Removing and installing camshaft“ |
| q | Before installing, check that all ball studs and O-rings are inserted in the unit injectors → Fig. |
| 9 - | Washers |
| q | For cylinder head bolts |
Caution
|
| 10 - | Hydraulic bucket tappet |
| q | Checking → Chapter |
| q | Removing and installing → Chapter „Renewing valve stem oil seals“ |
| q | Do not interchange (mark allocation) |
| q | Place down with contact surface facing downwards |
| q | Check axial clearance of camshaft before installing → Chapter |
| q | Lubricate contact surface |
| 11 - | Valve cotters |
| 12 - | Valve spring plate |
| 13 - | Valve spring (outer) |
| q | Removing and installing with cylinder head installed → Chapter „Renewing valve stem oil seals“ |
| q | Remove and install with cylinder head removed using valve spring compressor -2037- |
| 14 - | Valve spring (inner) |
| q | Removing and installing with cylinder head installed → Chapter „Renewing valve stem oil seals“ |
| q | Remove and install with cylinder head removed using valve spring compressor -2037- |
| 15 - | Valve stem oil seal |
| q | Renewing → Chapter |
| 16 - | Valve guide |
| q | Checking → Chapter |
| 17 - | Unit injector |
| q | Removing and installing → Rep. Gr.23 |
| 18 - | Oil seal |
| q | Renewing → Chapter |
| 19 - | Valves |
| q | Checking → Chapter |
| q | Valve dimensions → Chapter |
| q | Do not machine; only grinding in is permitted |
Note
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