Via a wide ribbed V-belt, the crankshaft transmits power to the coolant pump and alternator. The 6-cylinder engine has a viscous-coupled radiator fan on the coolant pump shaft. If there is an air conditioner, then its rotation is transmitted to the compressor from an additional belt with ribs. Since the belts are located one behind the other, to remove the rear belt, you must first remove the belt in front of it.
The belts are tensioned automatically, there is no need to tighten them. Typically, the life of the belt is at least as long as the life of the vehicle. The belt must be replaced in the following cases:
- Crack formation.
- The appearance of noises, for example, when slipping in case of oil ingress.
- In the presence of damage such as: transverse cracks in the ribs, holes in the ribs, deposits of dirt and inclusions of small stones between the ribs, loosening or wear of the side surfaces of the rubber ribs, also refer to Section Checking the condition of drive ribbed belts.
If the removed belt is to be used later, the direction of rotation must be marked on it with chalk.
Replacing the A/C Compressor Drive V-Belt
The operation of lifting and placing the vehicle on stands is dangerous! Therefore, before carrying out the operation, read Section Jacking and towing.
1. Raise and place the vehicle on stands. Turn away bolts of fastening and remove the bottom cover of an impellent compartment, address to the Section Removal and installation of the bottom cover of an impellent compartment.
2. Version with hydraulic tensioning element: Insert a socket wrench into the screw on the idler pulley. If there is a protective cap, first remove it. As a result of slow clockwise rotation, the hydraulic tensioning element -1- is compressed. Remove the V-belt.
3. Version with mechanical tensioning element: Press the tensioning element at the hexagon -1- in a clockwise direction. Remove the V-belt.
4. Put a new V-belt on the pulleys. In this case, the tension roller, as when removing, turn completely to the right. The V-belt must be flush with the pulleys and must not protrude from the side.
5. Slowly unload the idler. The tension force is determined by the tension element. The tension value is not adjustable.
6. Establish the bottom cover of an impellent compartment. Lower the car onto its wheels.
Replacing the alternator drive V-belt
Models 320i, 323i, 328i
The V-belt drives the alternator, coolant pump and power steering pump.
7. Models with air conditioning: Remove the viscous radiator fan, refer to Section Removing and installing a viscous fan.
8. Use a screwdriver to remove the cover from the roller (arrow illustration).
9. Insert a socket wrench into the screw on the idler pulley and slowly turn it clockwise (arrows in the illustration). As a result, the hydraulic tensioning element is removed. Remove the V-belt.
10 Slide a new V-belt over the pulleys as shown. At the same time, tighten the tension roller as when removing. The V-belt must lie flush with the pulleys and must not protrude from the side.
In the version with an additional tensioning roller -1-, the rotation lock on the axis of the additional tensioning roller must be fixed in the groove of the generator.
11. Slowly unload the tension roller. The tension force is determined by the tension element. The tension value is not adjustable.
12. Put the cover on the tension roller.
13. Models with air conditioning: Install the radiator fan, refer to Section Removing and installing a viscous fan.
Model 320d
The V-belt drives the alternator, coolant pump and power steering pump.
14. Remove the radiator shutters, refer to Section Removal and installation of the fan/fan shroud.
15. Insert the square of the 1/2" socket extension as a lever into the hole on the tensioner.
16. Slowly turn the head extension clockwise. This compresses the tensioning element in a compressed state and insert the rod, for example, a drill through the hole -1- into the hole in the holder.
17. Put a new V-belt on the pulleys according to the above diagram, while compressing the tensioner, as shown in the accompanying illustration. The V-belt must lie flush with the pulleys and must not protrude from the side.
The position of the alternator may differ from that shown in the accompanying illustration, but the belt routing must be as shown in the illustration.
18. Unload a tension roller and remove the lever. The tension force is determined by the tension element. The tension value is not adjustable. If a rod was used, remove it by unloading the tension element.
19. Install the radiator shutters, refer to Section Removal and installation of the fan/fan shroud.