4-cylinder 8-valve engine
Removing
Remove air filter, see chapter «Supply system».
Remove upper toothed belt guard, see above.
Remove cylinder head cover 9 Set crankshaft to TDC for cylinder 1, see chapter «Ignition system».
Attention: Do not change the engine setting any more.
Loosen the toothed belt and remove it only from the camshaft gear, see above.
Lock the camshaft sprocket at the front with a punch. Unscrew and remove the gear wheel, if it does not give in, it is easy to tap it with a rubber mallet. Remove segment key.
Mark all bearing caps, see illustration.
Remove covers 1 and 3. Then release covers 2 and 4 crosswise.
Diesel engine: first remove covers 5, 1 and 3. Then release covers 2 and 4 crosswise.
Pull out the camshaft.
Attention: If the poppets need to be removed, they must be marked so that they can be installed in the same place during installation. Poppet pushers working surface (camshaft side) lay down.
Installation
The camshaft is marked by embossing numbers and letters between the intake and exhaust cams.
Attention: Replacement cylinder heads are partially supplied with bearing shells for the camshaft. In this case, there are 2 different versions: 1 - cylinder head with cleanly machined bearing beds, camshaft for a camshaft of nominal size (diameter a = 26.00 mm, for AEK engine: a = 25.97 mm, for AFT, AGE engines: a = 34.00 mm). 2 - a cylinder head with cleanly machined camshaft bearing beds and a camshaft with a shaft journal diameter less than the nominal (diameter less than the nominal a = 25.75 mm and a yellow dot on the designation VW-AUDI). A camshaft with a journal diameter smaller than the nominal diameter is not available as a spare part; if necessary, install a camshaft with a nominal journal diameter and the appropriate bearing shells.
If necessary, the camshaft can be checked for runout in a workshop before installation. Wear limit: 0.01 mm.
If a used camshaft is reinstalled on engines with high mileage or noise in the valve drive, it is advisable to check its axial clearance. Wear limit 0.15 mm. The measurement is carried out with the poppets removed and bearing caps installed 1 and 4, for diesel engines 1 and 5
Install a new camshaft seal. Before installation, it is easy to lubricate the working lip and the outer edge of the stuffing box
The plug must be replaced.
Install the bearing caps as a test and pay attention to the offset of the mounting holes relative to the middle. The bearing caps must be installed so that the holes in the caps line up with the holes in the cylinder head. Pay attention to the markings on the bearing caps.
If the poppets have been removed, they must be installed in the same places. Pushers are easy to lubricate and do not warp during installation.
Attention: Poppet pushers must not be interchanged.
Lubricate the camshaft and install.
Attention: The cams of cylinder 1 must point upwards. Install the bearing caps in accordance with the markings. Pay attention to center offset: Tighten caps 2 and 4 crosswise to 20 Nm.
Install bearing caps 1 and 3 and tighten to 20 Nm.
Diesel engine: Fit bearing caps 5, 1 and 3 and tighten to 20 Nm. In this case, fit the bearing cover 5 with light blows of a plastic hammer to the end surface of the camshaft.
Insert the camshaft sprocket key. Fit camshaft sprocket and tighten to 80 Nm. While doing this, hold the camshaft gear with a punch.
Place toothed belt on camshaft sprocket. Pay attention to the correct position of the intermediate shaft and belt pulley, see above.
Pull on the toothed belt see above.
Replace the cylinder head cover gasket with a new one, carefully tighten the cover bolts to 10 Nm. In a carburetor engine, together with the cylinder head cover, fasten the bracket for the fuel stilling chamber.
Install the toothed belt guard.
Caution: If new poppets are installed, the engine must not be started for about 30 minutes, otherwise the valves will collide with the pistons.
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