Dismantling
Remove the air filter. Remove the upper timing belt cover.
5-cylinder engine: remove the upper part of the intake manifold.
Remove the cylinder head cover.
Set the crankshaft to TDC of the piston of the 1st cylinder.
Note: Do not change the engine position again.
Loosen the timing belt and remove it upwards from the camshaft wheel.
5-cylinder engine: remove the ignition distributor.
Secure the camshaft gear at the front with a suitable rod. Unscrew and remove the camshaft gear, otherwise knock it out with light blows of a rubber hammer. Remove the camshaft key.
Mark all bearing caps.
Remove the 1st and 3rd bearing caps. Then loosen the 2nd and 4th alternately crosswise.
Diesel engine: First remove bearing caps 5, 1 and 3, then loosen bearing caps 2 and 4 alternately in a crosswise pattern.
Remove the camshaft.
Note: If the plate tappets are removed, they must be replaced so that they can be reinstalled in their original position. Place the tappets with the working surface (camshaft side) down.
Installation
The camshaft is marked with numbers and letters stamped between the intake and exhaust cams.
Note: For the 4-cylinder petrol engine, the cylinder heads are partly supplied with bearing shells. There are two versions: a cylinder head with machined journals for using a normal-sized camshaft (journal diameter = 26.00).
Caution: Cylinder head with machined bearing beds and camshaft with reduced main journal size (journal size = 25.75 mm and yellow dot on VW-AUDI sign). The latter camshafts are not available as spare parts, a normal size camshaft with the corresponding bearing shells must be used.
Before installing a long-life camshaft, it must be checked for radial play. Its permissible value is 0.01 mm.
If a camshaft with a long service life is installed or if there is noise in the operation of the valve timing mechanism, it is necessary to check the axial (longitudinal) clearance. Its permissible value is 0.15 mm. The measurement is performed with the plate tappets removed and the 1st and 4th bearing caps installed, for a diesel engine the 1st and 5th.
Install a new camshaft oil seal. Lightly lubricate the installation areas.
If the rear plug is damaged, replace it.
Install the bearing caps. Check that there is no lateral displacement. The holes in the caps and the cylinder head must match.
If the plate tappets were removed, they must be installed in place. Lightly lubricate the tappets and insert them into place without skewing.
Note: The tappets are not replaceable.
Lubricate and install the camshaft.
Note: The cams of the 1st cylinder must be facing upwards. Install the bearing caps in accordance with the marks. Watch the axial offset; tighten bearing caps 2 and 4 alternately crosswise with a force of 20 Nm.
Install bearing caps 1 and 3 and tighten to 20 Nm.
Diesel engine: Install bearing caps 5, 1 and 3 and tighten to 20 Nm. At the same time, adjust bearing cap 5 with light blows of a polymer hammer.
Insert the camshaft gear key. Put the gear on and tighten it to 80 Nm. Hold the gear with a suitable rod.
Place the toothed belt on the pinion. Ensure that the intermediate shaft and V-belt pulley are installed correctly.
Tighten the timing belt.
For the cylinder head cover, use a new seal, carefully tighten the cylinder head cover bolts to 10 Nm.
5-cylinder engine.
Install the ignition distributor.
Install the upper intake manifold.
Install the timing belt cover.
Install the air filter.
Caution: If new bucket tappets have been installed, the engine must not be started for approximately 30 minutes, otherwise the valves may collide with the pistons.