N43TU engine
Withdrawal
1. The oil pump is an integral structure with the chain case.
2. Remove the chain case as described in paragraph 9.
Inspection
3. On the reverse side of the chain housing, remove the screws and remove the oil pump cover to gain access to its rotors (pic. 17.3.a, b).
4. Check that there are pi markings on the upper ends of the rotors for their correct relative position. If there is no such marking, apply it yourself. Remove the rotors from the housing (pic. 17.4, a, b).
5. Thoroughly clean the pump housing and rotors, then reinsert the rotors into the housing, observing the markings.
6. Use a feeler gauge to measure the gap between bore 8 in the pump housing and the outer rotor (pic. 17.6). Place the edge of a steel ruler on the end of the pump housing and use flat feelers to measure the axial clearances between the surfaces of the rotors and the pump plane.
7. If the clearance is too large, consult your BMW dealer regarding the possibility of replacing parts or the pump assembly.
8. If the clearances are correct, remove the rotors, pour some engine oil into the housing, then insert and rotate the rotors to lubricate all the mating parts of the pump.
9. Install the pump cover and tighten its fastening screws to the required torque.
10. To check the pressure reducing valve, remove the spring ring from the valve body, remove the sleeve, spring and plunger. Since the manufacturer does not specify the length of the valve spring in the free state, compare its length with a new spring (pic. 17.10, a-g).
11. Reassemble the valve in reverse order.
Installation
12. Install the chain case on the motor as described in paragraph 9.
N42 engine
Withdrawal
13. On these engines, the oil pump is structurally integrated with the balance shaft housing. The pump cannot be separated from the shafts. Remove the oil pan. as stated in paragraph 13.
14. Turn out two bolts of fastening of an oil intake pipe. unscrew the pipe from the pump and pull it down (rice: 17.14).
15. Turn the crankshaft to the TDC position of the piston No. 1 (see paragraph 3). Lock the flywheel in this position.
16. Turn away a nut of fastening of an asterisk of the oil pump. Attention! The nut has a left-hand thread.
17. Depress the pump drive chain tensioner and fix it in the depressed position by inserting a rod of suitable diameter into the tensioner hole (pic. 17.17).
18. Remove the bolts securing the lower chain guide to the oil pump housing and balancer shafts.
19. With a piece of wire, pull the sprocket off the oil pump shaft (pic. 17.19).
20. Ask an assistant to hold the housing and unscrew the 8 bolts. Lightly press down on the back of the case, then pull it back (pic. 17.20). After removing the assembly, remove the damper from the dowel pins. It is not recommended to disassemble the assembly.
21. To replace the oil pump drive chain, remove the timing chain as described in paragraph 7. Remove the plug to the right of the crankshaft and remove the screw securing the upper part of the oil pump drive chain tensioner (pic. 17.21).
22. Pull the tensioner down with the damper. The tensioner can only be separated from the damper after they have been removed.
Installation
23. Put the pump drive chain on the crankshaft sprocket (if the chain has been removed before). Install the timing chain (see paragraph 7).
24. Reinstall the oil pump chain tensioner and guide. Screw in the tensioner mounting screw and tighten it until hand-tight.
25. Make sure. that the alignment pins of the balance shaft housing are in place. Insert the pump drive shaft and balance shafts into the sprocket and reinstall the housing, aligning the dowel pins with the holes. Lubricate the threads of the mounting bolts and screw them into the appropriate holes. Tighten the bolts to the required torque.
26. With a piece of wire, pull the sprocket off the oil pump shaft (see fig. 17.19).
27. Align the flats of the balancing shafts with two straight metal strips and fix them in this position with a clamp (see fig. 7.49.a, b). Keep in mind that the wider slots at the ends of the balance shafts should be at the top (closer to the roots).
28. Make sure that the crankshaft is fixed in the installation position. Slide the sprocket onto the shaft splines. Pull out the pin that fixes the chain tensioner and check the position of the balance shafts again. If the shafts are misaligned or the sprocket splines do not line up with the shaft splines, rotate the balance shafts 360°and try again. It is possible that it will be possible to put on an asterisk not from the first, and not even from the second time.
29. After the shafts are aligned and the sprocket is put on the splines, screw in the tensioner / damper mounting screws and tighten them securely. Screw in the plug.
30. Screw on the sprocket mounting nut and tighten it to the required torque.
Attention! The nut has a left-hand thread.
31. Install the oil pickup pipe, replacing the O-ring on it. Tighten the pipe bolt securely.
32. Remove the crankshaft retainer. Install the oil pan.