Audi Workshop Service and Repair Manuals

Renewing valve stem oil seals with cylinder head installed

Special tools and workshop equipment required

t	Puller -3047 A-

t	Fitting tool -3129-

t	U/J extension and socket, 10 mm -3220-

t	Removal and installation device -VAS 5161-

Procedure The Audi A3 with 4-cylinder 1.9 ltr. and 2.0 ltr. 2-valve TDI engines is equipped exclusively with NGK ceramic glow plugs.   Note NGK ceramic glow plugs are colour-coded with a „white seal (on some versions painted over in silver)“ but do not have a chamfered shoulder at the tip.   Caution Important: Always observe the special instructions for handling ceramic glow plugs. Handling ceramic glow plugs:   Caution t  Due to the special properties of the material used, ceramic glow plugs are easily damaged and require extra care when handling and removing/installing. Always observe the special instructions when removing and installing ceramic glow plugs → Rep. gr.28. t  Use only the approved type of ceramic glow plugs → Electronic parts catalogue. t  Transport and store only in original packaging or packed separately in bubble wrap. t  Do not remove new ceramic glow plugs from packaging until they are ready to be fitted. t  Ceramic glow plugs are sensitive to knocks and bending. For this reason, ceramic glow plugs which have been dropped (even from a height of only about 2 cm) must not be installed, even if no damage is apparent (hair-line cracks may not be visible). t  Always install a new ceramic glow plug if you are not sure the old one is in perfect condition. t  Damaged glow plugs (e.g. heater pin of the glow plug is damaged) will invariably cause engine damage. t  If the heater pin of the glow plug is damaged, the fragments must be removed from the combustion chamber before starting the engine for the first time, otherwise this will invariably cause mechanical damage (piston seizure). –  Remove the camshaft → Chapter. –  Remove camshaft bearing shells from cylinder head.   Note t  Make sure that the used camshaft bearing shells are not interchanged (note marking). t  When installing the camshaft, make sure that the retaining lugs on the bearing shells are correctly seated in the bearing caps and the cylinder head. t  Make sure that the hydraulic bucket tappets are not interchanged; mark allocation on rear with a waterproof felt-tipped pen. –  Remove bucket tappets out of guides. –  Place bucket tappets down on a clean surface with contact surface facing downwards in the order in which they were removed.

–  Insert punch -VAS 5161/3- into bucket tappet guide. –  Knock valve cotters loose on all valves using a plastic hammer. –  Remove all glow plugs → Rep. gr.28. –  Set piston of the respective cylinder to „bottom dead centre“.

–  Screw adapter -VAS 5161/11- finger-tight into the glow plug hole of the relevant cylinder. –  Screw snap-in device -VAS 5161/6- with interlocking fork (M6) -VAS 5161/5- into threaded hole on cylinder head. –  Push guide bush -VAS 5161/16- as far as it will go into bucket tappet guide for valve to be removed. l  Installation position of guide bush: hatched areas are perpendicular to driving direction. –  Insert assembly cartridge -VAS 5161/15- into guide bush. –  Connect adapter -VAS 5161/11- to compressed air supply using a commercially available connection piece. l  Minimum pressure: 6 bar –  Attach pressure fork -VAS 5161/2- to snap-in device -VAS 5161/6- and push assembly cartridge down. –  At the same time, turn knurled screw of assembly cartridge clockwise until tips engage in valve cotters. –  Move knurled screw back and forth slightly; the valve cotters are thus forced apart and taken up by the cartridge. –  Release pressure fork. –  Remove assembly cartridge and guide bush. –  Remove valve spring plate and valve springs.

–  Detach valve stem oil seals using puller -3047 A-.   Note

A plastic sleeve -A- is included with the new valve stem oil seals. –  Insert plastic sleeve -A- onto the valve stem to prevent damage to the new valve stem oil seal -B-. –  Lightly lubricate sealing lip of valve stem oil seal. –  Slip valve stem oil seal over plastic sleeve. –  Carefully press valve stem oil seal down onto valve guide using fitting tool -3129-. –  Remove plastic sleeve.

–  If valve cotters have been removed from assembly cartridge, they need to be put into insertion device -VAS 5161/18- first.   Note Larger diameter of valve cotters faces upwards. –  Press assembly cartridge -VAS 5161/15- onto insertion device from above and pick up valve cotters. –  Insert valve springs and valve spring plate.

–  Reinstall the assembly cartridge -VAS 5161/15- into guide bush -VAS 5161/16-. –  Push pressure fork down and pull knurled screw upwards while turning to left and right - this will insert the valve cotters. –  Release pressure fork with knurled screw still in pulled position. –  Repeat procedure for each valve. Assembling Installation is carried out in the reverse order; note the following: –  Insert bucket tappets. –  Install camshaft → Chapter. –  Install glow plugs → Rep. gr.28.   Note t  After installing the camshaft, the engine must NOT be started for about 30 minutes. The hydraulic tappets have to settle (otherwise valves will strike pistons). t  After working on the valve gear, turn the engine carefully at least 2 rotations to ensure that none of the valves make contact when the starter is operated.