Cylinder head
1 – cylinder head; 2 – camshaft bearing cap; 3 – oil supply pipe; 4 – cylinder head gasket; 5 – cylinder head cover; 6 – partition; 7 – cylinder head cover gasket; 8 – valve guide; 9 – valve seat; 10 – technological plug; 11 – hairpin
Unscrewing the cylinder head mounting bolts
Removal
The cylinder head is removed on a cold engine together with the intake and exhaust manifolds.
Location of intake manifold mounting bolts on fuel injection engines
Removal the coolant supply hose from the fitting at the rear of the cylinder head
Disconnecting the electrical connector from the coolant temperature sensor
Location of the bolts securing the drive chain cover to the cylinder head
1. Remove the ground cable from the battery.
2. Open and position the hood in a vertical position.
3. Drain the coolant from the cooling system.
4. Remove the air filter.
5. Remove the camshaft sprocket and upper chain guide.
6. Remove the auxiliary drive belt.
7. Disconnect the exhaust pipe from the exhaust manifold.
8. Remove the nuts securing the oil dipstick tube to the exhaust manifold.
9. Remove the accelerator cable from the throttle lever.
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10. Unbolt the strut from the intake manifold. On carburetor engines, unbolt the bolt securing the strut to the manifold. On fuel-injected engines, unbolt the two bolts and remove the throttle return spring (see Fig. Location of intake manifold mounting bolts on engines with fuel injection system).
11. Loosen the clamp and remove the coolant supply hose to the heater from the fitting at the rear of the cylinder head (see Fig. Removing the coolant supply hose from the fitting at the rear of the cylinder head).
12. Disconnect the electrical connector from the crankshaft angle sensor and the left four-pin connector from the ignition control unit.
13. Unscrew the nut and disconnect the wire from the clamp on the diagnostic connector mount.
14. Unscrew the diagnostic connector, then disconnect the gray connector from the back of the socket.
15. Disconnect the electrical connectors from the sensors located on the cylinder head and intake manifold (see Fig. Disconnecting the electrical connector from the coolant temperature sensor).
16. Disconnect the vacuum hoses from the cylinder head and intake manifold.
17. Remove the brake booster vacuum hose from the intake manifold fitting.
18. On fuel injection models, relieve fuel line pressure.
19. Disconnect the fuel supply and return hoses from the carburetor or fuel pressure regulator. Close the ends of the hoses with appropriate plugs.
20. On models with air conditioning, unscrew the air conditioning pipe bracket from the cylinder head.
21. Remove the generator.
22. Remove the three upper bolts securing the timing chain cover to the cylinder head (see Fig. Location of bolts securing the drive chain cover to the cylinder head).
23. Check that all wires and hoses are disconnected from the cylinder head.
24. Working in the reverse order of tightening (see Fig. Cylinder Head Bolt Tightening Sequence), loosen the cylinder head mounting bolts by 1/3 turn per pass until the bolts are completely loose.
25. Remove the cylinder head from the cylinder block.
26. Remove the cylinder head gasket.
Preparing the head for installation
Measuring the length of the cylinder head bolt
The maximum permissible bolt length is 122.0 mm.
1. The mating surfaces of the cylinder head and block must be completely clean. Use a hard plastic or wooden scraper to clean them. Be careful when cleaning, as the aluminum alloy is very easy to damage. Check that carbon deposits do not get into the oil and water channels. This is especially important for the lubrication system, as carbon deposits can block the oil supply to the engine components. If necessary, clean the channels, check the mating surfaces of the head and cylinder block for nicks, deep scratches and other damage. If the defects are small, they can be removed by mechanical processing. In case of significant defects, the parts are subject to replacement.
2. Using a metal ruler and feeler gauge, check the flatness of the mating surfaces.
3. Clean the bolt holes in the cylinder block. Driving a bolt into oil-filled holes can cause the block to burst due to hydraulic pressure.
4. Measure the length of the bolts from the base of the head (see picture). If the bolt length exceeds the allowable limits, replace all bolts in the set.
Installation
Caution! When installing the cylinder head, a new gasket must be used. Remove the gasket from its sealed packaging immediately before installing it on the cylinder block.
Cylinder Head Bolt Tightening Sequence
1. Install the manifolds onto the cylinder head.
2. Check that the crankshaft and camshaft timing marks are aligned with the pointers.
3. Check that the new cylinder head gasket is the same type as the original and that the TOP or OBEN marking is facing upwards. Install the cylinder head gasket onto the guide pins on the cylinder block.
4. Install the cylinder head onto the guide pins.
5. Apply a thin coat of engine oil to the threads and base of the bolt head. Insert the bolts into the cylinder head and tighten them finger tight at this stage.
6. Gradually and sequentially tighten all cylinder head mounting bolts to the specified torque and in several stages in the sequence shown in the figure.
7. Install the three bolts securing the top of the timing chain cover to the cylinder head.
8. Install the generator.
9. If equipped, install the air conditioning pipe bracket to the cylinder head.
10. Connect the fuel supply and return hoses.
11. Connect the brake booster vacuum hose to the intake manifold fitting.
12. Connect all previously removed hoses and electrical connectors to the cylinder head.
13. Connect the coolant supply hose to the heater to the rear of the cylinder head.
14. Install the mounting stand onto the intake manifold.
15. Connect and, if necessary, adjust the accelerator cable to the throttle lever.
16. Screw on the oil dipstick tube.
17. Connect the exhaust pipe to the exhaust manifold.
18. Install the auxiliary drive belt.
19. Install the upper timing chain guide and camshaft sprocket.
20. Install the air filter.
21. Fill the cooling system with coolant.
22. Connect the battery ground cable.