Secondary circuit
Withdrawal
1. Remove the camshaft adjuster as described in paragraph 9.
2. On the right side of the engine, unscrew the tensioner plunger assembly (pic. 7.2). The o-ring can be discarded - a new one is required for assembly.
Attention! The plunger assembly contains a stiff spring. Be careful.
3. If the tensioner assembly is to be used further, depress the plunger several times to force any remaining oil out of the tensioner assembly.
4. Press the piston of the secondary chain tensioner and fix it in this position by inserting a drill of a suitable diameter into the hole (pic. 7.4).
5. Unscrew the nut and remove the shaft position sensor rotor and leaf spring from the exhaust camshaft sprocket (pic. 7.5).
6. Turn off three nuts of fastening of an asterisk of an inlet shaft and remove a corrugated disk from an asterisk (pic. 7.6).
7. Turn out three screws of fastening of an asterisk of an exhaust shaft and remove a secondary chain together with asterisks (pic. 7.7). If you plan to use these parts in the future, save them so that they take their original position during assembly.
Inspection
8. If the sprocket teeth or chain are worn out, the chain should be replaced. A worn chain has a noticeable play of the links, the axles of the links have grooves at the ends. A worn chain makes noise when running. It is recommended to change the chain in any case when the engine is disassembled for overhaul. If the chain causes any suspicion, then in order to avoid further major troubles, it is better to replace it.
9. Inspect the sprocket teeth for wear. The teeth of the new sprocket look like an inverted V. When worn, a semicircular groove appears on the side surface of the working side of the tooth and the tooth takes the form of a hook. If the teeth are worn, the sprocket must be replaced. Also inspect the running surfaces of the tensioner shoe and chain guide for wear and replace them if necessary.
Installation
10. Make sure the #1 piston is still at TDC and that the crankshaft is locked in that position.
11. Make sure. that the primary chain and exhaust camshaft sprocket are in place. Screw the tool BMW 11 4 220 into the hole where the primary chain tensioner assembly is to be located and turn the screw of the tool until the screw contacts the tensioner shoe (pic. 7.11).
12. To set the correct relative position of the two sprockets, use BMW tool 116 180. Insert both sprockets into the chain and put everything together in the tool. If there is no tool, install the sprockets as follows. so that between the marked points (pic. 7.12) 16 chain rollers were laid.
13. Put the sprockets on the ends of the camshafts so that the slots on the spitz surfaces of the sprocket and the intake shaft are aligned (pic. 7.13).
14. Insert the ring gear into the intake camshaft sprocket as follows. so that its lock slots fit into the corresponding slots of the sprocket and shaft (pic. 7.14). Slide the ring gear into the sprocket until approximately 1 mm of the ring remains visible.
15. Install the corrugated disc on the input shaft sprocket with the FRONT mark forward. Screw on the nuts, but tighten them only by hand.
16. Screw the screws into the exhaust shaft sprocket, tighten them to a torque of 5 Nm, then unscrew them by 180°.
17. Install the friction disc and leaf spring on the exhaust shaft sprocket with the F mark forward. If the mark is not visible, install the leaf spring with the convex side forward (pic. 7.17).
18. Install the shaft position sensor rotor on the exhaust shaft so that the arrow on the rotor coincides with the plane of the cylinder head under the gasket (pic. 7.18). Screw on the nuts and tighten them until hand-tight.
19. Pull the ring gear out of the exhaust shaft as far as possible.
20. Press the plunger of the secondary target tensioner and pull out the locking rod (or drill).
21. Using a torque wrench, tighten the adjusting screw on the fixture screwed into the hole for the primary chain tensioner assembly to 0.7 Nm. If a suitable torque wrench is not available, screw in the screw as far as it will go. to remove all the slack in the chain. Check for slack by trying to turn the exhaust sprocket by hand.
22. To check the correct alignment of the sprockets, install BMW 116150 fixture in place of the valve timing regulator. Install the fixture on the phase regulator studs (without gasket) and evenly tighten the nuts so that the tool is fully in contact with the cylinder head. This device sets the position of the ring gears and holds them while tightening the sprocket bolts/nuts (pic. 7.22). without this device, it is impossible to set the initial phases of the camshafts, so its use is mandatory.
23. Gradually and evenly tighten the sprocket nuts/bolts to 1st stop torque (see technical data). Tighten the slotted screws of the exhaust sprocket first, then the nuts of the same sprocket, and then tighten the nuts of the intake sprocket. In the same sequence, first tighten the screws and then the nuts to the 2nd stage torque. After tightening the fasteners, without removing special tools 116 150, remove the flywheel retainer and templates that fix the camshafts. Rotate the crankshaft two full turns and reinsert the retainer into the flywheel.
24. Check up position of camshafts, inserting templates, be convinced that. that the shafts are in the correct position.
Note. Due to the fact that the sprockets are rubber coated, as well as due to the presence of tolerances in the connections, a misalignment of the device for fixing the intake shaft with the square flange may occur up to 1 mm. The mutual arrangement of the shafts in this case should be considered satisfactory.
25. Remove tool 11 6 150 and reinstall the phase regulator (see paragraph 9).
Primary circuit
Withdrawal
26. Remove the secondary circuit as described in the previous paragraph.
27. Remove the gear ring from the exhaust shaft sprocket and remove the flange with internal slots from it.
28. Remove the four bolts and remove the primary chain tensioner (pic. 7.28).
29. Remove three pins from the exhaust sprocket (pic. 7.29), lift the chain and remove the sprocket from the shaft. Notice which side the sprocket is mounted on.
30. Remove the chain cover as described in paragraph 6.
31. Remember laying of a chain concerning a tensioner and a damper.
32. Disconnect the chain from the crankshaft sprocket and pull it out of the engine. Chain shoe, if it gets in the way, move as needed (pic. 7.32).
Attention! After removing the chain, do not rotate the crankshaft and camshafts, as there is a risk of sticking the pistons into the valves.
33. If necessary, you can now remove the tensioner shoe. To do this, remove the spring retainer from the end of its axis (pic. 7.33).
34. In the same way, you can remove the chain damper, for which you need to remove the upper and lower spring clips. Be careful - the latches are fragile and easily washed (pic. 7.34).
Installation
35. Be convinced that the No. 1 piston is in TDC of the end of a step of a compression, and that the cranked shaft is fixed in this position. Using the template, also check the position of the camshafts.
36. Put the chain on the crankshaft sprocket.
37. Reinstall the tensioner shoe and chain guide (if they were removed). Lay the chain relative to the tensioner and damper in the same way as before disassembly. Secure the shoe and damper with spring clips. Be careful - the latches break easily.
38. Turn the exhaust camshaft sprocket so that the arrow on the sprocket is aligned with the upper plane of the cylinder head, and put the chain on the sprocket (pic. 7.38). Then put the sprocket on the shaft.
39. Install the chain cover as described in paragraph 6.
40. Screw tool 11 4 220 into the hole for the tensioner assembly (see paragraph 9) and turn the adjusting screw of the fixture until its tail touches the tensioner shoe. In this case, the exhaust shaft sprocket may turn slightly. If necessary, reposition the sprocket relative to the chain so that the arrow on the sprocket is still aligned with the top plane of the cylinder head.
41. Screw three studs into the sprocket and tighten them to the required torque.
42. Install the secondary chain tensioner and securely tighten its bolts.
43. Install the internally splined flange onto the sprocket so that the cutout in the flange formed by the missing spline is aligned with the same cutout on the splined end of the shaft. Insert the ring gear into the flange so that its locking (wide) the splines fit into the corresponding cutouts in the flange and at the end of the shaft (pic. 7.43).
44. Push the ring gear in until the threaded holes in the sprocket are centered on the elongated holes in the flange (pic. 7.44).
45. Install the chain as indicated in p.p. 10-25 of this paragraph.