The above procedure for removing and installing the cylinder head is given on the example of cars with gasoline engines. Features of removal and installation of a head of the block of cylinders at diesel engines are stated at the end of the chapter.
Removal and installation of the head are made without dismantling the engine from the engine compartment.
Removing
1. Disconnect the wire terminal «masses» (-) from the battery terminal by turning off the ignition.
Attention! Disconnecting the battery from a radio with an anti-tampering access code will delete the specified code, as well as the settings on the radio. Therefore, before disconnecting the battery, make sure that the code is recorded and that it can be re-entered into the radio after the battery is connected. If the code is unknown to the owner of the car, then only a specialized workshop or its manufacturer can put the radio into operation.
2. Drain the coolant from the cylinder block cooling jacket.
3. Remove the cylinder head cover, see relevant chapter.
4. Remove the block of ignition coils, see relevant chapter.
5. Disconnect a reception pipe from a final collector.
6. Cars with an air pump. Remove the air shutoff valve.
7. Remove the thermostat, see relevant chapter.
8. Set the piston of cylinder No. 1 to the TDC position. Cylinder number 1 is located near the ribbed belt.
To set the cylinder piston to TDC, turn the engine crankshaft so that the TDC mark on the belt pulley is set opposite the mark on the timing chain cover.
In this piston position of cylinder #1, the lobes of the camshaft should be facing away from the valves.
To rotate the crankshaft, remove the right front wheel and fender liner. Insert a long hex wrench through the hole in the wing (insert) 17 mm, for example HAZET-986-17, fixing it on the extension handle, and put it on the head of the central bolt of the belt pulley on the crankshaft.
9. Mark the position of the camshaft drive sprocket and camshaft drive chain by drawing a line along the chain and sprocket with a marker.
10. Unscrew bolts of fastening of a chain tensioner 1 and remove it (see arrows in illustration).
11. Remove the sprocket from the camshaft. When unscrewing the sprocket mounting bolts, hold the shaft by the belt from turning.
12. Remove the drive chain from the camshaft sprocket.
13. Support the engine from below with a garage lift by placing a block of wood on top of it.
14. Unscrew the bolts securing the front support 1 of the engine to the bracket 2 of the engine mount (see illustration).
15. Remove both socket head cap screws from the chain case.
16. Loosen in several passes on a cold engine all the cylinder head bolts, acting in the reverse order of their tightening (see illustration 4.25), and then completely unscrew the bolts.
17. Measure the length of the cylinder head bolts.
The length of the new bolts is 183 mm (L = 183 mm) (see illustration). With each tightening, the bolts are stretched in length and this elongation is maintained. If the length of the bolts is 186 mm or more, then they must be replaced with new ones without fail. It is recommended that only new bolts be installed after each removal of the cylinder head.
18. Remove the head from the cylinder block using the services of an assistant.
Installation of a head of the block of cylinders is carried out in an order, the return to removal.
19. Clean the mating surfaces of the head and cylinder block.
20. Examine a head of the block of cylinders and be convinced that it is not bent and has no cracks.
21. Clean the holes for the cylinder head bolts.
22. Apply sealant, such as Loctite 5900, to the jumper between the cylinder head and the timing cover.
Attention! After applying the sealant within 10 minutes, lay the gasket and install the cylinder head.
23. Lay on the block of cylinders a new sealing lining.
24. Establish a head of the block of cylinders into place.
The position of the cylinder head is centered by dowel pins in the cylinder block. When installing the head, make sure that the head sits on the dowel pins.
Attention! The cylinder head bolts must be tightened with great care. Before tightening, check the accuracy of the torque wrench. To facilitate the work, you can use an angle template, for example, HAZET 6690 (see illustration).
Attention! If an angle template is not available, then the bolt angle must be calculated. To do this, position the wrench handle on the angle template along the engine and turn in one continuous motion until the handle is perpendicular to the engine.
25. Tighten the cylinder head bolts in sequence from 1 to 10 in several passes (see illustration).
- 1st pass. Tighten the bolts with a torque wrench to 35 Nm.
- 2nd pass. Tighten the bolts 90°with a wrench.
- 3rd pass. Tighten the bolts 90°with a wrench.
26. Tighten the mounting bolts 11 and 12, with which the cylinder head is attached to the cover of the gas distribution mechanism with a force of 20 Nm (see illustration 4.25).
27. Install the front engine mount and screw it to the engine bracket with a force of 55 Nm (see illustration 14.2).
28. Lower the garage lift and remove the wood block.
29. Check up position of a camshaft. With the piston of cylinder No. 1, the mark on the camshaft flange must be centered on the mark on the camshaft bearing cap.
Make appropriate adjustments if necessary.
Attention! Before turning the camshaft, turn the crankshaft so that it is at an angle of 30°after TDC to avoid hitting the valves and piston crowns and damaging them.
30. Install the sprocket on the camshaft and secure it with a new socket head bolt with a tightening torque of 20 Nm. Then tighten the bolt by 60°.
31. Lay the camshaft drive chain so that the marks made on the chain and on the sprocket before dismantling match.
32. Check again the initial position of the camshaft.
33. Install the chain tensioner, replacing its old gasket with a new one.
Attention! Pay attention to the correct installation, because. the hole is slightly off-center.
34. Tighten the chain tensioner bolts. The tightening torque is 8 Nm.
35. Establish a final collector on fingers of a head of the block of cylinders, having laid before it a new sealing lining. Before installing the manifold, inspect the threaded pins and replace if necessary. install a new gasket screw the exhaust manifold to the cylinder head. Screw the collar nuts onto the pins and tighten them to 40 Nm.
36. Check engine oil level.
37. Warm up the engine to operating temperature and check the tightness of all connections. The tightness of the cooling system is checked using a device for pumping it only after the engine has warmed up to operating temperature.
Attention! The cylinder head gasket becomes sealed only after the engine warms up to operating temperature and the gasket swells.
Diesel vehicles
The procedure for removing and installing the cylinder head is similar to dismantling and installing on cars with gasoline engines, except that on diesel engines, the removal and installation of injectors, camshafts and balancers is necessary. The tightening torques of the main threaded connections are also given below.
38. Measure the length of the M-12 bolts securing the cylinder head. The length of the new bolts is 186 mm. With each tightening, the bolts are stretched in length and this elongation is maintained. If the length of the bolts has reached 188 mm or more, then they must be replaced with new ones without fail.
39. Lubricate the threads and head surfaces of the new bolts.
40. Tighten the cylinder head bolts in the same sequence as in vehicles with gasoline engines, i.e. from 1 to 10 in several passes.
- 1st pass. Tighten the bolts with a torque wrench to 60 Nm.
- 2nd pass. Tighten the bolts with a wrench by 180°.
41. Tighten the cylinder head bolts to the timing cover with a force of 20 Nm.
42. Set the piston of cylinder No. 1 to TDC and fix the camshafts in this position by inserting two cylindrical pins with a diameter of 6 mm into the holes on the drive shaft sprockets.
With the crankshaft at TDC on cylinder No. 1, the pins must be in contact with the cylinder head.
Tightening torques for threaded connections:
- exhaust manifold collar nut - 21 Nm
- hairpins (fingers) exhaust manifold mountings - 11 Nm
- sprocket to camshaft - 18 Nm
- camshaft bearing cap to cylinder head - 9 Nm
- front/rear timing cover - 9 Nm
- timing chain tensioner - 89 Nm