Toothed belt work

As already mentioned, the valves are controlled by a toothed belt. It drives the camshaft (s) with half the crankshaft speed. In addition, it is a water pump drive.

The toothed rubber belt is of great importance in our Opel engines. The small combustion chambers do not allow one of the valves to be open and therefore extended into the combustion chamber while the corresponding piston moves up to its highest position. This situation can occur if the toothed belt breaks or jumps over several teeth on the belt pulley. Then the valve hits the piston crown and in no time the engine is damaged. Therefore, the toothed belt is replaced every four years or when a mileage of 60,000 km is reached. Checking the tension of the toothed belt is not carried out as part of the inspection. The installed toothed belt, which must be removed during installation, must also always be replaced with a new one.

Removing the front toothed belt cover

• Remove the air filter housing, see the air filter chapter.
• Mark the direction of rotation of the V-ribbed belt. Loosen the belt and remove it from the belt pulleys, see chapter «Generator».
• 1.6L engine: unscrew the top part of the front toothed belt cover or remove it from the clips.
• Unscrew the V-ribbed belt pulley from the crankshaft. To do this, block the flywheel with the KM-911 tool
• Unscrew the lower part of the front toothed belt cover or remove it from the clips. Pull the toothed belt cover up out of the engine compartment.
• When installing, tighten the toothed belt cover to 4 Nm.
• Screw on the V-ribbed belt pulley with a new center bolt with 8-valve engine 1.6 l at 55 Nm +45°+15°and with 16-valve engine 1.6 l at 95 Nm +30°+15°.
• 1.8 and 2.0 liter engines: remove the torque arm, see generator chapter.
• Unscrew the front toothed belt cover or remove it from the clips. Where required, unscrew the V-ribbed belt pulley. To do this, press the central bolt of the toothed belt drive pulley in the opposite direction. Tightening torque 20 Nm.
• When installing the torque arm, tighten it to 60 Nm.
• Tighten the toothed belt cover to 8 Nm.
• For all: distance dimension to the encoder, check with a template: the specified value is 1.0±0.7 mm. If the gap size is not correct, replace the encoder holder.

Removing the rear toothed belt cover

8 valve engine

Remove the front toothed belt cover

• Set the 1st cylinder to the TDC position of the ignition moment.
• Remove the crankcase ventilation hoses from the cylinder head cover. Dismantle the cable duct. Unscrew fixing bolts of a cover of a head of the block of cylinders and remove a cover.
• Unscrew the toothed belt tensioner on the oil pump.
• Remove the toothed belt.
• Remove the timing belt drive pulley from the crankshaft. Pay attention to the installation position!
• Unscrew the camshaft pulley, to do this, with an open-end wrench, press the camshaft by the hexagon in the opposite direction.
• Unscrew fixing bolts of a back cover of a gear belt and take out a cover from an impellent compartment upwards.
• Tightening torques: toothed belt rear cover on oil pump and camshaft housing 12 Nm, camshaft pulley on camshaft 45 Nm, toothed belt tensioner on oil pump 20 Nm (pay attention to the mounting position).
• Apply a toothed belt, take into account the valve timing. Check toothed belt tension.
• Install the front toothed belt cover.

Removing the rear toothed belt cover

16-valve engine 1.6 l

• Remove the toothed belt.
• Remove the cylinder head cover.
• Unscrew both camshaft pulleys.
• Unscrew the toothed belt guide pulley from the cylinder head on the intake side.
• Remove the toothed belt tensioner from the oil pump.
• Remove the toothed belt drive pulley from the crankshaft.
• Unscrew the rear toothed belt cover from the cylinder head and from the oil pump
• Installation: Screw on the toothed belt cover with a tightening torque of 4 Nm.
• Slide on the toothed belt drive pulley. Observe the installation position!
• Toothed belt tensioner on oil pump - 20 Nm.
• Toothed belt guide roller on cylinder head - 25 Nm.
• Mount the camshaft pulleys see later in this chapter.
• Apply a toothed belt, take into account the valve timing. Check the installation of the toothed belt tensioner and water pump, see section «Checking the toothed belt tension».

Removing the rear toothed belt cover

16-valve engine 1.8 and 2.0 l

• Remove the toothed belt.
• Remove the cylinder head cover.
• Unscrew both camshaft pulleys
• Unscrew the camshaft position sensor and the adapter located under it from the cylinder head.
• Unscrew the toothed belt tensioner and guide from the engine block (ie) video clip (And).
• Unscrew the guide roller holders from the engine block.
• Remove the toothed belt drive pulley. Press the drive pulley in the opposite direction with the KM-662-B tool and unscrew.
• Unscrew the rear timing belt cover from the cylinder head and from the oil pump.
• Installation: Tighten the toothed belt cover to 6 Nm.
• Install the timing belt drive pulley with a new bolt (130 Nm + (40°-50°). Check the condition of the elastic washer.
• Mount the camshaft pulleys see later in this chapter.
• Toothed belt tensioner on oil pump - 25 Nm, guide roller holder on engine block - 25 Nm, guide roller on holder - 25 Nm, adapter on cylinder head - 60 Nm, camshaft position sensor on cylinder head - 6 Nm.
• Apply toothed belt. Consider the valve timing. Check the position of the toothed belt tensioner and water pump, see section «Checking the toothed belt tension».