The cylinder head is usually removed to replace its gasket, valves, valve guides, head repair, as well as for complete engine repair
The cylinder head can be removed complete with the receiver, intake pipe, fuel rail and catalytic converter, or by first removing these components.
Dismantling and installation of the head must be performed on a platform or on a lift.
Remove the engine screen.
Relieve the fuel pressure in the power system.
Disconnect the negative terminal from the battery.
Disconnect the fuel supply hose from the fuel rail tube.
Drain the coolant from the engine.
Remove the air filter.
Remove the vacuum brake booster hose from the receiver pipe.
Disconnect the tips of the high-voltage wires from the spark plugs.
Using a 13mm socket, unscrew the nut securing the tip of the negative wire to the outlet pipe of the cooling system and remove the wire tip from the stud.
After loosening the clamps, remove the cooling system hoses from the outlet pipe and from the thermostat housing
Remove from the fittings of the throttle assembly the hose that drains coolant from the heating unit of the assembly and the hose of the solenoid valve for purge the adsorber.
Disconnect the air supply hose from the throttle body nozzle.
Disconnect the wiring harness blocks of the engine management system and the wiring harness blocks of the fuel injectors and from the idle air control system as well as from the sensors:
- - throttle position;
- - phases;
- - coolant temperature;
- - oxygen concentration.
Disconnect the wire blocks from the coolant temperature indicator and emergency oil pressure sensors.
By loosening the lower fastening nut and unscrewing the upper fastening nut of the coolant pump pipe bracket, remove the bracket from the cylinder head stud.
Remove the left and right support brackets of the intake pipe.
Disconnect the additional muffler pipe from the catalytic collector.
Remove the cylinder head cover.
Remove the camshaft gear pulley (see How to replace the camshaft oil seal of a VAZ-21114 engine).
Using a 10mm wrench, unscrew the nut of the upper fastening of the rear timing belt cover.
Use a 10mm hex to unscrew the ten screws securing the cylinder head.
Remove the screws and washers.
Remove the cylinder head assembly with the receiver, intake pipe, fuel rail and catalytic collector (it is more convenient to remove the head with an assistant).
Remove the cylinder head gasket.
If it is necessary to disassemble the cylinder head, we dismantle the receiver, intake pipe and catalytic collector.
Remove the camshaft (see “Removing the camshaft”).
Having marked the installation location, remove the valve pushers with adjusting washers from the sockets of the block head cylinders.
Using a 13mm socket, unscrew the two nuts securing the exhaust pipe
Remove the pipe
Remove the gasket
Unscrew the coolant temperature gauge sensor.
We mark the valves with a marker.
When disassembling the valve mechanism, place a stop (a wooden block) under the plate of the valve to be disassembled.
We dry out the valve (see “Replacing valve oil seals”) and remove the spring plate, outer and inner springs, and support washer
Remove the valve from the guide sleeve.
We dismantle other valves in the same way.
Before assembling the cylinder head, use a wire brush to remove carbon deposits from the surface of the combustion chambers.
We wash the cylinder head with kerosene and blow out the oil channels with compressed air.
We assemble and install the cylinder head in the reverse order.
Before installing the valves, clean them of carbon deposits and apply a thin layer of engine oil to the valve stems.
We clean the mating surfaces of the cylinder block, head and exhaust pipe from the remains of old gaskets, dirt and oil.
Remove oil and coolant from the threaded holes of the cylinder block for the head mounting screws.
We install a new cylinder head gasket and the head itself using two centering bushings.
Install the fastening screws and tighten them in four steps according to the diagram:
- first step - tighten the screws to a torque of 20-25 Nm (2.0-2.5 kgcm);
- second step - tighten the screws to a torque of 70-85 Nm (7.0-8.5 kgcm);
- third technique - turning the screws 90°;
- the fourth step is to turn the screws 90˚.
The cylinder head bolts can only be reinstalled if they have been stretched to a length of no more than 135.5 mm.
If the length is longer, replace the screws with new ones.