Attention! To perform this operation, you will need a BMW 113 360 fixture. It is extremely difficult to manufacture such a fixture on your own due to its complex design and high requirements for manufacturing accuracy. Do not attempt to remove the camshafts without this tool, as this may cause damage that will result in the need for costly repairs.
Withdrawal
1. Remove the VANOS regulator as described in the previous paragraph.
2. Remove the secondary chain of the timing mechanism, as indicated in paragraph 7.
3. Remove the flange and ring gear from the exhaust camshaft sprocket.
4. Remove secondary target tensioner (see fig. 8.13).
5. Remove the three pins from the exhaust sprocket, lift the chain and remove the sprocket from the end of the shaft. Notice which side the sprocket is mounted on.
6. Remove the retainer from the flywheel, then, while holding the primary chain taut, rotate the crankshaft 30°counterclockwise to prevent accidental sticking of the pistons into the open valves. Tie the primary chain to the cylinder head with a piece of wire so that it does not fall into the engine and disengage from the sprocket.
7. If necessary, unscrew the studs from the end of the intake shaft and remove the shaft position sensor rotor (pic. 10.7)
8. Remove the installation template from the camshafts.
9. Turn out spark plugs.
10. Check if there is a marking on the camshaft covers. The covers should be numbered starting at the front of the engine and the numbers should be easy to read from the exhaust side. The exhaust shaft covers are marked A1 to A7, and the intake shaft covers are marked E1 to E7.
11. Turn out from a head of cylinders four hairpins of fastening of a cover of camshafts (pic. 10.11).
12. Loosen the #1 cover nuts and remove the cover so that it does not jam when the shaft is removed (pic. 10.12).
13. Shafts are removed one by one. Install special tool 11 3 260 on the cylinder head. Screw its bolts into the spark plug holes. Install the device so that the plungers are located above the covers of the corresponding shaft (those. inlet or outlet) (pic. 10.13).
14. Turn the eccentric shaft of the tool with a wrench by its flats to press on the camshaft covers (pic. 10.14).
15. Turn away nuts of other covers.
Attention! Do not unscrew the cap nuts without a tool - the camshaft or its bearings may be damaged.
16. Remove pressure from the covers and remove the tool from the cylinder head.
17. Remove the bearing covers, then lift the camshaft. Keep the support covers in such a way that they take their original places during assembly.
18. Now you can remove the support block from the cylinder head. The support block must be removed very slowly, since the pushers will be released when the support is raised and may pop out of their sockets. The danger is that in this case the pushers can be mixed up and it will not be possible to install them in the future in their original places.
19. After removing the support block, pull out the valve lifters one by one. Lay out the pushers in a certain sequence, which will allow you to install them in their original places. Store tappets upright in containers filled with oil.
20. To remove the second camshaft, repeat the same steps.
Inspection
21. Clean and wash all parts, including shaft bearings and their covers. Inspect parts for wear and damage. Especially carefully inspect the bearings and cam surfaces for chips and pitting. Also inspect the tappet surfaces for wear and tear. Replace defective parts.
Installation
22. If the camshaft bearing blocks have been removed, check whether the mating surfaces of the bearings and cylinder head are clean enough. Check if the mounting sleeves are in place, which should be located on the studs of supports No. 2 and 7 (pic. 10.22).
23. Install the support blocks and valve lifters in their places.
24. The simplest thing is to fix the pushers in the support and install them in place as an assembly.
25. Lubricate the tappet bores in the shaft support block with engine oil (do not lubricate until the end surfaces of the pushers) and insert the pushers and the block of supports to their original places.
26. After installing all the pushers in the support block, the pushers must be fixed in the block so that they do not fall out of it when the support block is installed on the cylinder head.
27. Establish the block of support with pushers on a head of cylinders. Please note: the intake shaft support block is marked A and the exhaust shaft support block is marked E. After installing the support blocks, the shaft markings should be on the side of the primary circuit and point towards each other.
Attention! Valve lifters not loaded with cam force. can increase their length. If the camshaft is quickly installed, then there is a danger that the closed valves, under the action of the elongated pushers, will go down and bump into the pistons.
28. To prevent the valves from sticking into the pistons after installing the camshafts, before returning the crankshaft to the TDC position, take a break of at least the following:
29. First identify the shafts so as not to mix them up. The intake shaft has a triangular flange at the front end, and the exhaust shaft has a round flange. Make sure the crankshaft is still rotated 30°counterclockwise from TDC.
30. Lay the camshafts in the supports so that the front cams of the intake and exhaust shafts are directed towards each other. The sides of the square flanges at the rear ends of the shafts must be strictly perpendicular to the upper plane of the cylinder head (can be checked with a square), and the hole side of the flange should be on top. After installing the exhaust shaft, put the primary chain on its front end.
31. Install the camshaft bearing covers in accordance with their markings. The exhaust shaft covers are marked A1 to A7, and the intake shaft covers are marked E1 to E7.
32. Install tool 11 3 260 over the covers and secure it to the cylinder head, as in the disassembly process.
Attention! Do not attempt to complete the installation of the camshafts without this tool.
33. Press the appropriate shaft covers by turning the tool's eccentric shaft.
34. While pressing the covers, screw on the nuts securing the covers and tighten them by hand as far as possible.
35. Tighten the support cap nuts to the required torque in diagonal sequence.
36. After tightening all nuts, unscrew and remove the cover pressure tool.
37. Install the second shaft in the same way.
38. Screw in the spark plugs and camshaft cover studs.
39. Insert a template to check the installation of camshafts. If necessary, rotate the shafts using the flats on them until the template is in place.
Attention! Read the caution after step 27 before continuing.
40. Rotate the crankshaft 30°clockwise to TDC and insert the flywheel retainer.
41. Install the camshaft sprockets and timing chains. as stated in paragraph 7.
42. Install the VANOS phase regulator assembly as indicated in paragraph 9.
43. To prevent the valves from sticking into the pistons after installing the camshafts, before turning the crankshaft with a starter, take a break of at least the following: