Removing and installing camshaft timing chain - vehicles with engine codes CNSB, CNTC, CHHB — AUDI

🧭 Before you start

Fits: Audi A3 (8V, 2012–2020); platform code 85

• Timing position: the crankshaft or camshaft is set and locked during this job
• Special tools named: T10352/2, T40271/2

Don't miss

• Turn vibration damper to "“TDC”" position using counterhold tool T10355.
• Turn exhaust camshaft in direction of (arrow A) using counterhold tool T10172 A and hold in place. Remove bolt (1) and guide tensioning rail (2) downwards.
• Check TDC position of crankshaft; flat surface of crankshaft (arrow) must be horizontal.
• Use a waterproof pen to mark cylinder block (1), as shown.
• Mark tooth (1) of three-part chain sprocket adjacent to marking (2) using waterproof pen.

🔧 Engine codes this applies to

📋 Procedure

1. Remove timing chain cover (top) .
2. Remove noise insulation (1)General body repairs, exterior66Noise insulation; Removing and installing noise insulation.
3. Remove wheel housing liner (right-side) General body repairs, exterior66Wheel housing liners; Removing and installing wheel housing liner (front).
4. Turn vibration damper to "“TDC”" position using counterhold tool T10355.
5. Remove timing chain cover (bottom) .

6. ⚠ The timing valve has a left-hand thread. — Turn assembly tool T10352/2 in direction of (arrow) to remove timing valve.
7. Remove bolts (arrows) and detach bearing saddle.
8. Remove bolts (arrows).
9. Screw in assembly lever T40243(arrows).
10. Compress and hold circlip (1) for chain tensioner.
11. Push assembly lever T40243 slowly in direction of (arrow) and hold in place.
12. Hold chain tensioner in position with locking tool T40267.
13. Remove assembly lever T40243.
14. Bolt camshaft clamp T40271/2 onto cylinder head and slide it into teeth of chain sprocket in direction of (arrow 2). If necessary, rotate inlet camshaft using assembly tool T40266(1).
15. Bolt camshaft clamp T40271/1 onto cylinder head.
16. Turn exhaust camshaft in direction of (arrow A) using counterhold tool T10172 A and hold in place. Remove bolt (1) and guide tensioning rail (2) downwards.
17. Continue turning exhaust camshaft clockwise (arrow A) until camshaft clamp T40271/1 can be pressed into teeth (C) on chain sprocket in direction of (arrow B).
18. Use screwdriver to release catch (arrow) and press off guide rail (1) towards front.
19. Unscrew bolts (arrows) and remove chain tensioner (1).
20. Press retainer for oil pump chain tensioner in direction of (arrow) and lock in place using locking pin T40011.
21. Unscrew bolt (1) and remove chain tensioner (2).
22. Unscrew bolts (1) and remove guide rail (2).
23. Remove camshaft timing chain from camshaft sprockets and place onto camshaft journals (arrows).
24. Remove chain tensioner for balance shaft timing chain (1).
25. Unscrew bolts (1), and remove tensioning rail (2) and guide rails (3) and (4).
26. Loosen tensioning bolt (A) and remove clamping pin (B).
27. Remove three-part chain sprocket assembly; to do so, remove oil pump chain.
28. Detach camshaft timing chain and drive chain for balance shaft.
29. Check TDC position of crankshaft; flat surface of crankshaft (arrow) must be horizontal.
30. Use a waterproof pen to mark cylinder block (1), as shown.
31. Mark tooth (1) of three-part chain sprocket adjacent to marking (2) using waterproof pen.
32. Turn idler gear/balance shaft to markings (arrow) (do not slacken bolt (1)). [Note: The drive chain links with coloured markings must be positioned at the markings on the chain sprockets.There is no need to note the position of any other coloured links.]
33. Fit drive chain for balance shafts; links with coloured markings (arrows) must be positioned at markings on chain sprockets.
34. Install guide rail (1) and tighten bolts (arrows).
35. Fit camshaft timing chain so that markings (arrows) are positioned on camshaft journals.
36. Fit oil pump chain onto three-part chain sprocket assembly.
37. Swivel three-part chain sprocket assembly towards engine in direction of (arrow) and fit on crankshaft. The marks (arrows) must align.
38. Screw clamping pin T10531/2 into crankshaft and hand-tighten.
39. Attach turning-over tool T10531/3. Screw on flange nut T10531/4 and hand-tighten. Move turning-over tool back and forth slightly using open-end spanner, 32 mm; at the same time, tighten flange nut until chain sprocket is firmly seated on teeth of crankshaft. Now (and not before) tighten tensioning bolt (A).
40. Position link of drive chain for balance shafts with coloured marking (arrow) at marking on three-part chain sprocket assembly. Install tensioning rail (1) and guide rail (2), and tighten bolts (3).
41. Install chain tensioner (1).
42. Check setting again; links with coloured markings (arrows) must be positioned at markings on chain sprockets.
43. Fit camshaft timing chain onto inlet camshaft, exhaust camshaft and crankshaft. Position links with coloured markings (arrows) at markings on chain sprockets.
44. Install guide rail (2) and tighten bolts (1).
45. Install top guide rail (arrow).
46. Use counterhold tool T10172 A to turn exhaust camshaft slightly in direction of (arrow A) and slide camshaft clamp T40271/1 out of teeth on chain sprocket in direction of (arrow B).
47. Release camshaft in direction of (arrow C) until timing chain is in contact with guide rail (1). Hold camshaft in this position, install tensioning rail (2) and tighten bolt (3).
48. Install chain tensioner (1) and tighten bolts (arrows).
49. Install chain tensioner (2) and tighten bolt (1). Remove locking pin T40011; support wire must come into contact with opening (arrow) on sump (top section).
50. Turn inlet camshaft in direction of (arrow 1) using assembly tool T40266. Slide camshaft clamp T40271/2 out of teeth on chain sprocket in direction of (arrow 2) and release camshaft.
51. Remove camshaft clamps T40271/1 and T40271/2.
52. Check setting; links with coloured markings (arrows) must be positioned at markings on chain sprockets.
53. Fit and tighten bolts (arrows). Tightening torque
54. Lubricate hole (arrow) with engine oil.
55. Attach bearing saddle and screw in bolts (arrows) hand-tight.
56. Remove locking tool T40267.
57. Tighten bolts (arrows) for bearing saddle .
58. Install timing valve .
59. Turn engine two rotations in direction of engine rotation. [Note: Due to the ratio, the timing chain links with coloured markings are no longer aligned after the engine has been turned.]
60. Detach turning-over tool and install timing chain cover (bottom) . [Note: Only tighten bolts (1) and (4) to final tightening angle after installing the vibration damper. The bolts must be unscrewed again to install the vibration damper.]

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