- Valve timing checked, new toothed belt fitted (traction side is tight, otherwise correct adjustment is not possible).
- 8-valve engine: turn the crankshaft by hand two revolutions in the direction of engine rotation and then return it to the ignition TDC position. Are the valve timing correct?
- When the toothed belt tension is correct, the arrow on the movable part of the tensioner is opposite the mark on the tensioner base plate.
- To adjust the tension of the toothed belt, slightly loosen the water pump mounting bolts and turn the eccentrically located pump with the KM-421-A tool clockwise. The movable part of the tension roller should now be at the right stop.
- If you do not have a special tool at your disposal, you can take a gas wrench to rotate the water pump.
- Tighten the bolts, crank the engine twice and put it back to TDC.
- Turn the water pump again so that the arrow and the mark on the tension roller match
- Tighten water pump bolts (8 Nm), rotate the engine twice and recheck the toothed belt tension.
- 16V: first check the basic setting of the water pump. The lug on the pump must align with the corresponding opposite piece on the engine block. If necessary, turn the water pump accordingly. Tighten the water pump bolts to 25 Nm.
- Rotate the crankshaft twice by hand in the direction of engine rotation and then return to TDC. Are the valve timings correct?
- The tension of the toothed belt is correct if the pointer and the mark on the tension roller match.
- To adjust, loosen the tension roller fixing bolt and tighten the adjusting eccentric counterclockwise until the arrow on the tension roller is at the right stop of the mark.
- Tighten the tension roller fixing bolt in this position (20 Nm).
- Rotate the crankshaft twice by hand in the direction of engine rotation and then return it to TDC.
- Loosen the idler pulley mounting bolt again.
- Turn the adjusting eccentric clockwise until the arrow and mark on the tension roller match, tighten the tension roller.
- Turn the engine over twice and return to TDC.
- Recheck the toothed belt tension.
Setting the valve timing
The valve control and the crank mechanism work in concert only with correctly set valve timing Incorrectly set valve timing leads to poor engine power and in extreme cases can cause even severe engine damage if the piston base hits valves that are not closed in time.
The figures show checking and adjusting the toothed belt tension in a 16-valve engine.
Left: Check the installation position of the water pump.
On right: Loosen the tensioner roller mounting bolt and tighten the adjusting eccentric counterclockwise until the arrow on the tensioner roller is at the right stop of the mark. Tighten the tension roller mounting bolt.
In a 1.6-liter 16-valve engine, the valve timing is set correctly if the mark on the crankshaft belt pulley is opposite the arrow on the engine block. Simultaneously marks (arrows in the photo on the left) on the front sides of the camshafts should be opposite each other and coincide with the top edge of the cylinder head. On a 1.8 / 2.0 liter 16-valve engine, the marks on the camshaft pulleys must be at the same height as the marks on the toothed belt rear cover (photo on the right).
- The toothed belt has been removed.
- On an 8-valve engine, turn the camshaft pulley so that the mark on the front of the pulley is at the same height as the mark on the rear timing belt cover.
- Make sure none of the pistons are at TDC when the camshaft is rotating, otherwise the valves or piston bases may be damaged.
- On a 1.6L 16 valve engine, rotate the camshaft pulleys so that the marks on the front sides of the pulleys are opposite each other and line up with the top edge of the cylinder head.
- In this case, too, no piston should be in the TDC position.
- On 1.8L and 2.0L 16 valve engines, turn the camshaft pulleys so that the marks on the front sides of the pulleys are at the same height as the marks on the rear toothed belt cover.
- In this case, too, no piston should be in the TDC position.
- For all engines: At the timing belt drive pulley fixing bolt, turn the crankshaft until the dash mark on the timing belt drive pulley aligns with the center of the milling on the oil pump housing (8 valve engine) or with a mark on the back cover of the toothed belt (1 6V).
- Put on a new toothed belt (side of the tensile force is stretched). Don't change the position of the camshaft again (ov) and crankshaft.
- Check toothed belt tension.
Tip: To avoid mistakes: the valve timing does not change as it wears. They are installed only once if the toothed belt has been removed before.
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