Note: Disassembly and repair of the cylinder head are described in chapter 2B.
Withdrawal
1. Before starting work, disconnect the negative battery cable as described in chapter 5A.
2. Drain the engine oil as described in chapter 1B.
3. Drain the coolant as described in chapter 1B.
4. Remove the accessory straps as described in paragraph 6. To do this, you will have to move the entire front panel away from the car to provide enough working space.
5. On A/C models, loosen the tensioner bolts and move the tensioner pulley up to loosen the drive belt tension. Remove the belt from the crankshaft pulleys, compressor and tensioner. Remove the air conditioning compressor from the mounting bracket and tie it up to the side without disconnecting the refrigerant pipes.
6. Remove the viscous fan coupling as described in paragraph 5 of chapter 3. To do this, you can insert a hexagon from behind, holding the assembly motionless with a fork tool fixed in the pulley holes. If the Audi tool is not available, make a homemade one from two strips of metal, reinforcing the bolts at the ends "forks" to align with pulley holes.
7. Remove the air filter as described in chapter 4B.
8. Disconnect the hose from the turbocharger pressure block to the right of the engine.
9. Turn away bolts of fastening of the turbine to catalytic converter. Release the front clamp of the exhaust system and take it back, disconnect the exhaust pipe and the catalytic converter from the turbocharger.
Note: Be careful not to damage the flexible connector of the exhaust system.
10. Loosen the clamps and remove the right intake duct leading from the air filter to the turbocharger.
11. If installed, remove the turbine support brackets.
12. Turn away a connecting bolt and disconnect a returnable oil tube from the block of cylinders.
13. Loosen the clamp and carefully disconnect the upper hose to the left of the cylinder head. Then disconnect the small bleed hose from the top of the expansion tank. Take the hose aside.
14. Loosen the nuts and remove the fuel pipes to the injectors (all at the same time).
15. Disconnect wiring from glow plugs.
16. Loosen the clamp and disconnect the cooling hose from the lower left side of the cylinder head.
17. Remove the top cover and remove the valve cover as described in paragraph 7 (pic. 11.17).
18. Set the engine to TDC as described in paragraph 2.
19. Remove the timing belt tensioner, injection pump sprocket and camshaft as described in paragraph 5.
20. Remove the rear timing belt cover from the cylinder block (pic. 11.20, a, b).
21. Remove the inlet air tube installed at the rear of the engine. To do this, loosen the clamps and disconnect the short hoses from the turbine and intake manifold, disconnect the hoses and wiring and remove the tube.
22. Remove the timing belt as described in paragraph 4. Remove the camshaft sprocket as described in paragraph 5.
23. Loosen the union nut, disconnect the oil supply pipe from the turbine.
24. Loosen the clamp and disconnect the heater outlet hose from the flange at the rear of the cylinder head (pic. 11.24).
25. If necessary, disconnect the gasket from the three heater elements on the flange at the rear of the cylinder head.
26. Disconnect the fuel return hose from the injectors.
27. In front of the cylinder head, disconnect the wiring attached to the top cover bracket.
28. In sequence, reverse tightening (see fig. 11.57 a), gradually loosen the cylinder head bolts half a turn per pass until all bolts can be removed "by hand". Discard the bolts - new ones will be required for installation.
29. Once again, make sure that everything from the head is disconnected and set aside. Remove the head from the cylinder block. If necessary, ask an assistant to assist, as the head is quite heavy, especially if removed together with manifolds (pic. 11.29).
30. Remove the gasket from the block, following the guide bushings. If the bushings have a loose fit, remove them and fold them so as not to lose them. Do not throw away the gasket yet - it will be required to identify a new one.
31. If the head is to be disassembled for repair, refer to the description chapter 2B.
Removal of manifolds and assembly
32. With the head on a workbench, remove the turbocharger as described in chapter 4B.
33. Remove the RVG valve as described in chapter 4B.
34. On AZ, AFF and AHU engines, unscrew the nuts and remove the small heat shields from the front of the exhaust manifold (pic. 11.34).
35. Gradually unscrew the mounting bolts and remove the intake manifold from the head. Remove the gasket and discard it.
36. If necessary, remove the oil supply pipe and bracket from the exhaust manifold.
37. Gradually turn away nuts of fastening and remove an exhaust manifold from a head of cylinders. Remove gaskets and discard. Throw away self-locking nuts (with filler) and get new ones.
38. Clean the mating surfaces of both manifolds. Install the exhaust manifold with new gaskets and nuts. Lay the gaskets correctly so that they do not damage the intake manifold gasket. Tighten the exhaust manifold mounting nuts to the prescribed torque - see chapter 4B (pic. 11.30).
39. If necessary, attach the oil supply pipe to the exhaust manifold and tighten the bolt.
40. Install a new intake manifold gasket and reinstall the manifold. Install the mounting bolts and tighten them to the specified torque as described in chapter 4B (pic. 11.40, a, b).
41. Establish a heat-shielding screen on hairpins of a final collector, wrap and tighten nuts of fastening.
42. Install the RVG valve as described chapter 4B.
43. Install the turbocharger on the intake and exhaust manifolds - see chapter 4B.
Preparing for installation
44. Before installation, the mating surfaces of the head and cylinder block must be completely clean. Use a hard plastic or wood scraper to remove all traces of the old gasket and carbon deposits. Also clean the piston bottoms. Be extremely careful - surfaces are easily damaged. Remember that dirt should not get into the oil and water channels and the threaded holes for the bolts - plug them with plugs or seal with adhesive tape. To prevent carbon deposits from getting into the gap between the pistons and cylinders, apply a layer of thick grease to the gap - the grease can be easily removed after cleaning with a stiff brush. After cleaning, wipe everything with a clean, dry cloth.
45. Inspect the mating surfaces of the head and block for deep scratches, cracks, or other damage. Minor defects can be repaired with a fine scraper, but serious ones may require head replacement as head grinding is not allowed - see description chapter 2B.
46. If there is a suspicion that the head is bent, check the mating plane of the head with a steel ruler, as described in chapter 2B.
47. Drive the threads in the head bolt block with a tap. If there is no such tap, make a homemade one.
48. On the engines discussed in this chapter, if the timing belt is removed, the crankshaft is set to TDC and while rotating the camshaft, the pistons will hit the valves. Therefore, the camshaft must be blocked at TDC when installing the head on the block by inserting a fixing film into the slot in the heel of the camshaft. The crankshaft must also be set to the TDC of the first cylinder before the head is installed.
Installation
49. Locate the thickness markings on the old gasket. It should be either notches or holes and a catalog number. If you do not have to install new pores» the gasket must be installed - thickness.
50. If new pistons are installed, how to purchase a new gasket - calculate its thickness by measuring the protrusion of the pistons, as described in chapter 2B.
51. Lay a new gasket on the block, aligning it with the guide bushings. Make sure that the inscription TOP and the manufacturer's catalog number are on top.
52. Cut off the heads of the two old block head bolts. Saw through the slot under the screwdriver. Thus, convenient guides for installation in heads are obtained (pic. 11.52).
53. Together with an assistant, lay the head with manifolds on the cylinder block, aligning it with the guide bushings.
54. Turn out homemade guides.
55. Lubricate threaded parts and bottom surfaces of new bolt heads.
56. Gently lower the hole bolt one at a time (don't drop them) and at this stage wrap them "by hand" (pic. 11.56).
57. Working gradually in the indicated sequence, tighten the head bolts in the prescribed specifications stages with a suitable head torque wrench (pic. 11.57). Repeat this exercise in the same sequence for stage 2.
58. After all the bolts have been tightened to stage 2, again in the indicated sequence, tighten all the bolts to the prescribed specifications angle in the stage using a goniometer nozzle on the knob. If a goniometer is not available, apply angle marks with white paint before tightening the bolts to meet requirements Specifications. Then tighten all bolts to the angles prescribed up to stage 4 (pic. 11.58).
Note: Start start head bolts do not require broaching.
59. As described in paragraph 2, make sure the TDC marks match.
60. The rest of the procedure is the reverse of the withdrawal. To finish, do the following:
- A) Fill the cooling system with the correct type and quantity of fluid as described in chapter 1B.
- b) Fill the engine with the correct type and quantity of oil as described in chapter 1B.
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