Removal and installation cylinder heads and their covers (Audi Q7-4L-D)

1. The details of installing the cylinder heads and their covers are shown in illustrations 11.1ad using the example of the left row of cylinders.













To remove the oil filler neck, lift its lock, turn it counterclockwise and pull the neck out (see illustration 11.1e).

Cylinder head cover

2. Remove the injectors of the corresponding cylinder bank (see Chapter 4).

3. When working on the left bank of cylinders of CASA/CASB engines, remove the upper section of the intake manifold (see Chapter 4), remove the bracket from the cylinder head cover (5 in the illustration) electrical wiring, disconnect the connector (3) on the fuel distribution line and move the wiring to the side.



4. When working on the right bank of cylinders of CASA/CASB engines, remove the connector (see illustration 4.25) from the bracket, disconnect this connector and remove its bracket from the cylinder head cover.



Disconnect the connectors (1-3 in the illustration) and move the electrical wiring to the side.



5. Loosen the bolts (see illustration) cylinder head cover fasteners in a diagonal order, then completely unscrew them and remove the cover.



6. Installation is carried out in reverse order. Use new gaskets and O-rings. If the seals on the bolts are damaged, replace the bolts together with the seals. Tighten the cover mounting bolts diagonally in several passes.

Cylinder head for BUG/BUN engines

7. Drain the coolant (see chapter 3).

8. Remove the fuel injection pump drive toothed belt (see Chapter 4) and remove the fuel injection pump gear using the T40064 puller (see illustration).





9. Loosen the center bolt (1 in the illustration) the camshaft gear approximately 2 turns, holding it from turning with tool No. 3036.



10. Remove the camshaft timing gear using tool T10320 (see illustration).





11. Unscrew the bolts and remove the rear cover of the fuel injection pump drive belt (see illustration).



12. When working on the right cylinder head, disconnect the supply line (2 in the illustration) and the return fuel lines (2) from the high-pressure fuel pump and move them to the side.

Note: Fuel may remain hot even after the engine has been turned off.

13. Remove the upper and lower sections of the intake manifold on the corresponding side (see Chapter 4).

14. Remove the corresponding upper timing chain (see section 9).

15. Unscrew the hollow bolt (8 in illustration 11.1c) and disconnect the cooling system bleed valve tube



16. Remove the intermediate exhaust pipe on the corresponding side (see Chapter 4).

17. Remove the corresponding cylinder head cover (see subsection above).

18. When working on the right cylinder head, unscrew the bolt (see illustration) and remove the right coolant pipe from the cylinder head.



19. Loosen the cylinder head mounting bolts in the order shown in the illustration.



Then completely unscrew the bolts, carefully remove the cylinder head and place it on a soft surface, being careful not to damage the glow plugs.

20. When installing the cylinder head, follow these notes:

• Use new cylinder head bolts;
• Replace self-locking fasteners, as well as fasteners that require tightening to a certain angle;
• Mechanical processing of the cylinder head is not permitted;
• Replace sealing parts;
• Carefully remove any remaining sealing material from the mating surfaces of the cylinder head and block, avoiding the formation of long scratches;
• After cleaning, remove all dirt and abrasive materials;
• In the threaded holes in the cylinder block (for fastening the cylinder head) there should be no coolant or oil, otherwise the cylinder block may crack when tightening the bolts;
• Remove the new cylinder head gasket from its packaging only immediately before installation, handle it carefully, do not damage the silicone coating and shaped areas;
• If a reversible cylinder head is being installed with the camshafts installed, lubricate the mating surfaces between the rocker arms and cam lobes before installing the cylinder head cover;
• The plastic protection of open valves should only be removed immediately before installing the cylinder head;
• Place the gasket with the "OBEN" marking facing up, i.e. the part number should face the cylinder head;
• When installing a new cylinder head or its gasket, the coolant and engine oil should be replaced;
• After working on the valve train, carefully rotate the crankshaft by hand at least 2 revolutions to ensure that the valves do not touch the pistons.

21. Set the crankshaft and camshafts to TDC and lock them as described in paragraphs 9-11 Section 9.

22. Pay attention to the number of holes (1 in the illustration) and the part number (2) on the gasket.



The left and right cylinder head gaskets are different from each other. If the cylinder head or its gasket needs to be replaced, select a new gasket with the same number of holes as the old gasket. If the connecting rod and piston group parts have been replaced, it will be necessary to select a new gasket based on the piston protrusion at TDC (see Section 14).

23. Clean the mating surfaces from oil and grease. For further actions after applying the sealant, the relevant parts should be installed within 15 minutes.

24. Apply beads of sealant to both joints of the cylinder block and the lower timing chain cover according to the dimensions shown in the illustration (upper part).



Then place the new cylinder head gasket on the centering bushings on the cylinder block and apply the same beads of sealant to the top side of the gasket in the same areas (the bottom side is cont. illustrations).

25. Place the cylinder head and tighten the new bolts by hand. Tighten the cylinder head bolts in sequence (8-1 in illustration 11.19). with a force of 35 Nm, then with a force of 60 Nm, and then tighten twice to an angle of 90°.

Note: After this, tightening the bolts is not allowed.

26. Install the remaining parts in the reverse order of their removal.

Cylinder head for CASA/CASB engines

27. Drain the coolant (see chapter 3).

28. Remove the appropriate upper timing chain from the camshaft only (see Section 9).

29. Remove the upper section of the intake manifold (see Chapter 4).

30. Remove the cover of the corresponding cylinder head (see subsection above). When working on the left cylinder head, perform the steps described in paragraphs 31-37, and when working on the right cylinder head, perform the steps described in paragraphs 38-43. Then perform the steps described in paragraphs 19-26.

31. Remove the fuel injection pump drive toothed belt (see Chapter 4). Remove the camshaft timing gear (see paragraphs 9-10).

32. Unscrew the bolts securing the rear cover of the fuel injection pump drive belt (see illustration).



The lid itself remains in place.

33. Unscrew the bolt (2 in the illustration) feeler gauge tube guide.



34. Remove the union nuts (2 and 3 in the illustration), move the high pressure tube to the side and remove it.



35. Remove the T-shaped connection from the cooling system bleed hose (see illustration).



36. Disconnect the connector of the activator No. 2 "V275" of the intake manifold flap (see illustration).



37. Remove the bolts (arrows in the illustration) and remove the EGR connecting pipe (1).



38. Remove the right upper coolant pipe (see Chapter 3). Unscrew the bolts (arrows in illustration 11.34) and remove the fuel injection pump protective plate. Then, unscrew the union nuts (1 and 4), move the high-pressure fuel line aside, and remove it.

39. Remove the bolts (1 and 2 in the illustration) lifting eye and pump "V400" of the EGR radiator.



Move the wiring (arrow) to the side.

40. Disconnect the cooling system bleeder pipe (see illustration) and disconnect the electrical wiring connectors of the glow plugs of cylinders No. 2-3.



41. Disconnect the connector of the "V157" actuator of the intake manifold flap (see illustration).



42. Disconnect the feed (1 in illustration 4.27) and return (2) fuel lines from the air intake chamber dividing panel.

Note: Fuel may remain hot for some time after the engine is turned off. When disconnecting fuel lines, wrap the connection with a thick layer of cloth and slowly disconnect.

43. Remove the bolts (arrows in the illustration) and move the fuel distribution line to the side without disconnecting the fuel lines.

Note: The union nuts (1 and 2) are already loosened.