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. Apply the handbrake, jack up the front of the vehicle and install safety stands.
3. Remove the engine top covers.
4. Remove the timing belt as described in paragraph 4. To do this, you will have to remove the front bumper and take the hood lock bracket away from the car.
5. Drain the coolant as described in chapter 1A.
6. Disconnect the muffler downpipe from the exhaust manifold - see chapter 4C.
7. Pull the front pipe back and remove the gasket. On AEB and AJL engines (turbocharged) disconnect the crankcase ventilation hose that runs under the turbine, unscrew the two bolts securing the oil supply pipe to the cylinder head. Remove the heat shield, remove the turbine from the exhaust manifold.
7. Remove the air filter assembly along with the air flow sensor (DMRV), as described in chapter 4A. Remove the air duct connecting the throttle body to the air filter.
ADP, ADR, AFY, AEB and AJL engines
Note: On these engines, the cylinder head is removed with the exhaust manifold, but without the intake manifold.
8. Remove the intake manifold as described in chapter 4A.
9. If necessary, disconnect the wiring from the automatic camshaft adjuster.
AHL engines
Note: On this engine, the cylinder head is removed with both intake and exhaust manifolds.
10. Loosen the clamps and disconnect the lower radiator hose from the radiator and engine, remove the expansion tank. Disconnect the top hose from the cooling tube.
11. Loosen connections and disconnect fuel lines.
Note: Before removing the pipes, spread a rag around to collect the fuel escaping under pressure.
12. Disconnect the accelerator cable from the throttle body as described in chapter 4A, disconnect the vacuum hoses from the non-return valve and the vacuum brake booster.
13. Disconnect the wiring from the injectors, throttle position sensor (TPS) (not throttle body) and camshaft position sensor (on the left side of the engine). Disconnect the wiring from the intake air temperature sensor located on the intake manifold. Disconnect the wiring from the oil temperature sensor on the right side of the cylinder head.
14. Remove the intake manifold support brackets from the manifold and left side of the engine.
All engines
15. On the motor shield behind the engine, disconnect the electrical connector for the oxygen sensor wiring and disconnect the wiring itself.
16. Disconnect the heater hose from the flange at the rear of the cylinder head, disconnect the wiring from the coolant temperature sensor screwed in the same place. On ACR, AFY, AEB, and AJL engines, also disconnect the wiring from the second coolant temperature sensor at the rear of the cylinder head.
17. On engines AOR and AFY disconnect hoses from the top pipe of the cooling system established at the left on a head of cylinders. Unscrew the rear mounting bolts, then just loosen the front mounting bolt (tube bracket hole - slotted). Slide the tube back and remove it from the engine (pic. 11.17).
18. On ADP and AHL engines, disconnect high voltage wires from spark plugs and take wires aside.
19. Remove the valve cover as described in paragraph 7. To do this, on all engines except ADP and AHL, you will have to remove the ignition coil and high-voltage wires. On ADR engines, remove the oil baffle plate (pic. 11.19).
20. Using a Tox head, loosen the head mounting bolts one turn per pass in the reverse order of tightening (see fig. 11.28). Remove bolts with washers (fig 11.20, a, b).
Note: The head bolts have been modified from Tox head bolts to Ribe head bolts - two heads may be required to remove old style bolts and install new style bolts.
21. Having removed all the bolts, remove the cylinder head from the block upwards together with the exhaust manifold (pic. 11.21). If the head "dried up", tap it with a wooden mallet. Do not pry the head with any levers.
22. Remove the cylinder head gasket from the block (pic. 11.22).
23. If required, remove the exhaust manifold from the cylinder head as described in chapter 4B. On AHL engines, also remove the intake manifold as described in chapter 4A.
Installation
24. Thoroughly clean the mating surfaces of the cylinder head and block. Remove oil and coolant from the threaded holes in the block for the head bolts. If this is not done, not only will the bolt torque be incorrect; from hydraulic pressure when tightening the bolts, cracks may appear in the block - the block will have to be thrown away. Head bolts must be replaced with new ones without any conditions (note the note in paragraph 19). Install the exhaust manifold with a new gasket to the head as described in chapter 4B. On AHL engines, install the intake manifold as described in chapter 4A.
26. Lay a new gasket on the block, with the number and inscription OBEN TOP up. Audi recommends that the gasket be removed from the packaging only before installation.
27. Carefully place the head on the block, aligning it with the guide bushings. Do not use any adhesives or lubricants. Insert new head bolts with washers and tighten them by hand with a slotted head.
28. In the specified sequence (pic. 11.28, a, b) tighten the bolts in the first stage as indicated in Specifications.
29. Screw the bolts in the same sequence to the angles prescribed specifications for stage 2 (pic. 11.29).
30. Install the valve cover as described in paragraph 7.
31. On ADP and AHL engines, connect high voltage wires to spark plugs.
32. On engines ADR and AFY, install the lower tube of the cooling system on the left side of the cylinder head, tighten the mounting bolts and attach the hoses.
33. Attach the heater hose to the flange at the rear of the cylinder head, connect the wiring to the temperature sensor on the flange. On ADR engines. AFY, AEB and AJL, connect the harness to the second temperature sensor at the rear of the cylinder head.
34. Connect the wiring to the oxygen sensor and secure it in the connector.
AHL engines
35. Install the intake manifold support brackets and tighten their mounting bolts.
36. Connect the wiring to the injectors, TPS (on throttle body) and camshaft position sensor (front left on the engine). Connect the wiring harness to the intake air temperature sensor located in the intake manifold. Connect the wiring harness to the oil temperature sensor at the rear of the cylinder head.
37. Attach the accelerator cable to the throttle body as described in chapter 4A. Attach the vacuum hoses to the check valve and vacuum booster wires.
38. Attach fuel lines and tighten their connections.
39. Install the expansion tank, attach the upper hose of the cooling system to the tube, install the lower radiator hose and tighten the clamps.
Engines ADP, ADR. AFY, AEB and AJL
40. If necessary, connect the wiring to the camshaft adjuster.
41. Install the intake manifold as described in chapter 4A.
All engines
42. Install the air filter together with the MAF sensor as described in chapter 4A, install the air intake duct connecting the air filter to the throttle body.
43. Attach the muffler downpipe with a new gasket as described in chapter 4B. On AEB and AJL engines (turbocharged) install the turbine on the intake manifold with the heat shield. Fix the oil feed pipe with two bolts, attach the crankcase ventilation hose located above the turbine.
44. Install the timing belt as described in paragraph 4.
45. Fill coolant as described in chapter 1A.
46. Install engine top covers
47. Lower the car. Connect the battery as described in chapter 5A.
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