Removal and installation the timing belt (BMW 3 Series E30)

6-cylinder engines M20 (320i, 325e), M21 (324d/td)

As part of the maintenance schedule, the timing belt must be replaced every 4 years. If the timing belt is removed, it must be replaced regardless of its service life.

Removal

Set cylinder "1" to the top dead center position, see section "Removing and installing the ignition distributor".

Caution: On diesel engines, the dead center position of cylinder "1" is indicated by a mark on the pulley. In this position, lock the crankshaft with a rod (see section "Adjusting the start of delivery moment of the high pressure fuel pump on a diesel engine").

Loosen the front engine lifting eye.

Remove the alternator V-belt and move the tensioner bracket toward the alternator (see section "Removal and installation the alternator V-belt. Replacing the V-belt").

Petrol engines: Unscrew the power steering pump and, if installed, the air conditioning compressor and set them aside without disconnecting the connections.

Remove the radiator (see section "Removal and installation the radiator").

Remove the belt pulley and vibration damper from the hub.



Remove the vibration damper hub by unscrewing the central bolt "H" with a 27 mm wrench. At the same time, hold the hub from turning with a special device BMW 112150 "G".

Note: To loosen the bolt, a high tightening torque (400 Nm) must be applied.

Remove the washer with the "K" lug and tighten the bolt again by about 3 turns.

Pull the hub off the crankshaft with a suitable puller. Rest the puller shaft against the bolt head. Then return the bolt and remove the hub.

Petrol engines: Release the TDC sensor wire from the mounting on the timing belt cover. Pull out the TDC sensor.

Diesel engines: Unscrew the cylinder head cover.

Unscrew the timing belt protective cover and pull it upward.



Loosen the fastening of bolts "E" and "F" and press the tension roller "R" inward with screwdriver "S".

Tighten bolt "E".

Remove the timing belt.

Caution: When the timing belt is removed, do not turn the engine if possible, as this may cause serious damage to the pistons and valves

Installation, petrol engines

Caution: When applying the timing belt, the position of neither the camshaft, nor the intermediate shaft, nor the crankshaft must be changed. Otherwise, serious damage to the engine may occur or the engine will not develop full power.

After tensioning the timing belt, check the installation of the camshaft and crankshaft again.



Install the new timing belt, starting with the crankshaft timing pulley "1". Then install the timing belt "2" on the pulleys in the order of the numbers in the figure.

Tension

Remove all spark plugs.

Caution: When the spark plugs are removed, the engine can only be turned by the adapter on the toothed pulley of the camshaft.

Loosen bolts "E" and "F" and turn the engine by the adapter of the toothed pulley of the camshaft "N" in the direction opposite to the direction of rotation of the engine. In this case, the toothed belt is tensioned by the tension spring. Finally, tighten bolts "E" and "F" with a torque of 22 Nm.

Caution: If the bolt becomes loose when turning the camshaft timing pulley, tighten the mounting bolt to a torque of 70 Nm.

Turn the engine 1 revolution in the direction of engine rotation until the mark on the camshaft toothed pulley "N" coincides with the mark on the cylinder head (arrows). At the same time, the mark on the crankshaft flange "K" should also coincide with the protrusion on the cover.



Otherwise, remove the timing belt again, align the pulleys according to the markings and re-apply and tension the timing belt.

Installation, diesel engine

Fix the camshaft using the BMW device in the top dead center position of the 1st cylinder, for which there is a platform on the shaft near the cam of this cylinder. If necessary, make your own device. With a new toothed belt or if the car's mileage is less than 15,000 km, a 2.5 mm thick gasket should be placed on the exhaust valve side of the cylinder head.



Loosen the camshaft toothed pulley bolt. The camshaft toothed pulley must be able to rotate relative to the camshaft.



Insert the BMW rod or a homemade corresponding rod into the console through the hole in the toothed pulley of the high-pressure fuel pump. The rod fixes the toothed pulley of the high-pressure fuel pump in the top dead center position of the 1st cylinder.

Apply the toothed belt with the engine cold (room temperature, 15-35°C), starting with the toothed pulley "1" of the crankshaft. Then apply the toothed belt "Z" in accordance with the numbering in Figure W-1041.

Turn the tension roller by the bolt "F" (fig. W-1042) to the right with a torque wrench. Belt tension torque with a mileage of up to 15,000 km: 45 Nm, over 15,000 km: 35 Nm.

In this position, tighten the tension roller.

Tighten the camshaft timing pulley mounting bolt to a torque of 70 Nm.

Caution: Remove the locking rods of the high-pressure fuel pump and crankshaft toothed pulleys. Remove the camshaft lock.

Secure the cylinder head cover by tightening the bolts evenly. Replace the damaged gasket.

Remove the protective cover, insert the TDC sensor and secure the TDC sensor wire to the bracket.



Install the vibration damper hub. Install the bolt with the casting washer and tighten it to 410 Nm.

Screw on the vibration damper pulley.

Install the radiator (see section "Removing and installing the radiator").

Screw on the power steering pump and, if removed, the air conditioning compressor. Tighten the V-belt (see section "Replacing and tensioning the V-belt of the power steering pump").

Insert the timing belt guard.

Install and tension the alternator V-belt (see section "Removal and installation the alternator V-belt. Replacing the V-belt").

Screw on the front lifting eye and engine bracket.

Diesel engines: adjust the fuel injection start time (see section "Adjusting the start moment of the high pressure fuel pump on a diesel engine").