Water pump — removal and installation (BMW 3 Series E46)

Note: A new O-ring will be required during installation.

Removal

1. Drain the coolant (see chapter 1).

Engine N42

2. Loosen the power steering pump pulley mounting bolts and remove the accessory drive belt. Note that the water pump is bolted to the power steering pump and both units must be removed together. Loosen the two bolts that secure the water pump to the power steering pump (Fig. 8.2).



3. Raise the front of the vehicle and place it on reliable supports. Remove the engine crankcase guard.

4. Disconnect the three hoses from the thermostat (Fig. 8.4). The power steering hoses remain connected to the pump.



5. Remove the four screws securing the power steering pump to the cylinder block. On the front side of the cylinder block, remove the bolt securing the power steering pipe support bracket and remove the bracket.



6. Unscrew the previously loosened bolts securing the water pump to the power steering pump. Remove the sealing rings of the adapter from the water pump to the block - they will need to be replaced during assembly (Fig. 8.6).



7. If necessary, the water pump can be disconnected from the thermostat housing.

To do this, remove the thermostat cover together with the thermostat itself and unscrew the four screws securing the water pump to the thermostat housing.

8. The water pump can be opened to replace the seal. To do this, unscrew the six bolts and separate the two halves of the pump. The sealing ring can be discarded - a new one will be required during assembly (Fig. 8.8).

M43TU engine and 6-cylinder engines

9. On the 6-cylinder engine model, remove the viscous coupling cooling fan as described in paragraph 5.



10. Loosen the water pump pulley mounting bolts and remove the accessory drive belt.

11. Unscrew the pump pulley mounting bolts and remove the pulley (Fig. 8.11).



12. Unscrew the water pump mounting bolts and remove the pump from the engine. If the pump cannot be removed by hand, screw two M6 bolts into the threaded technological holes on both sides of the pump and press the pump with boots (Fig. 8.12).



13. Remove the sealing ring from the pump (Fig. 8.13).

Installation

Engine N42

14. If the water pump has been disassembled, replace the rubber seal. Connect the pump halves and tighten them securely with six bolts.

15. If the thermostat was removed, reinstall its housing and cover, replacing the sealing rings. Tighten the bolts securely.

16. Replace the sealing rings of the water pump adapter to the cylinder block, lubricate the rings with an anti-seize compound and insert the adapter into the pump.

17. Lubricate the water pump guide lugs with grease and align them with the corresponding lugs on the power steering pump.

18 Install the water pump onto the power steering pump and tighten the mounting bolts by hand.

19. Install the power steering pump to the cylinder block, making sure that the water pump adapter fits into the hole in the block. Securely tighten the power steering pump mounting bolts.

20. Tighten the bolts securing the water pump to the power steering pump to the specified torque.

21. Otherwise, installation is carried out in the reverse order of removal.

M43TU engine and 6-cylinder engines

22. Install a new sealing ring onto the water pump housing and lubricate it with grease to facilitate installation.

23. Install the pump in place and secure it with bolts and nuts. Gradually tighten the fasteners until the required torque is reached, making sure that the pump enters without tilting.

24. Install the pulley on the pump and screw in the bolts that secure it.

25. Install the accessory drive belt (see chapter 1) and tighten the pulley bolts securely.



26. Install the fan assembly as shown in paragraph 5.

27. Fill the cooling system with liquid.

[This publication was borrowed from an online resource: «BMWMAN.ru»]