Comment. The engine cylinder head can be removed as an assembly or after partial disassembly (remove camshafts). Both options are shown on engine 21124 (1,6i). On the engine 2112 (1,5i) work is done in the same way (see text for features).
Removing
1. Drain the engine coolant (see "Coolant - replacement").
2. Remove the rear timing belt cover (see "Camshafts for 2112 and 21124 engines (16v) - removal and installation").
3. Remove the cylinder head cover (see "Cylinder head cover for 2112 and 21124 engines (16v) - removal and installation").
Comment. If the cylinder head is removed for its subsequent repair, it is better to partially disassemble it before removal:
- A) remove camshafts (see "Camshafts for 2112 and 21124 engines (16V) removal and installation");
- b) remove the hydraulic pushers from the seats (see "Valve lifters for engines 2112 and 21124 (16V) removal and installation");
- V) remove the fuel rail (see "Fuel rail engine 2112 (1,5i 16V) - removal, disassembly, assembly and installation", or "Fuel rail engine 21124 (1,6 16V) - removal, disassembly, assembly and installation");
- G) remove the camshaft position sensor (see "Camshaft Position Sensor - Check and Replace");
- d) disconnect from the engine bracket the upper rod of the power unit (see "Top Mounting Rod for Engines 2112 and 21124 (16v)").
If disassembly of the cylinder head is not required (e.g. to replace the cylinder head gasket), it should be removed assembled with camshafts, bearing housing, fuel rail, oil pressure and camshaft position sensors.
4. Disconnect the upper rod of the power unit from the bracket of the cylinder head (see "Top Mounting Rod for Engines 2112 and 21124 (16v)").
5. socket wrench by 13 mm unscrew the three nuts securing the rod bracket.
6. Remove the bracket from the studs.
7. On engine 21124 remove exhaust manifold (see "Engine exhaust manifold 21124 (1,6i 16v) - removal and installation, gasket replacement"). On the engine 2112 remove exhaust manifold (see "Engine exhaust manifold 2112 (,5i 16V) - removal and installation, gasket replacement") and inlet pipeline (see "2112 engine intake manifold (1,5i 16v) - removal and installation, gasket replacement").
8. Key by 10 mm unscrew the bolt securing the wire end "weight" and disconnect it from the block head.
9. Key by 13 mm unscrew the nut securing the negative battery terminal wire and remove the terminal from the stud.
10. In order not to damage the sensor connectors, disconnect the wires from the coolant temperature sensors of the engine management system (see "Coolant temperature sensor - check and replace") and from the temperature gauge (see "Coolant temperature gauge sensor - check and replace"), as well as from the camshaft position sensor, if we remove the cylinder head assembly (see "Camshaft Position Sensor - Check and Replace").
11. socket wrench by 13 mm unscrew the two nuts securing the thermostat housing.
12. Remove the thermostat housing from the cylinder head studs and, without disconnecting the hoses, take it aside.
13. Remove the sealing gasket.
14. Hex key by 10 mm we turn off ten bolts of fastening of a head to the block of cylinders in the specified sequence.
The sequence of loosening the head bolts
15. Remove the head from the cylinder block assembly...
...or with the camshafts removed.
16. Remove the cylinder head gasket.
17. In order not to lose, we take out two guide bushings from the seats in the cylinder block.
Installation
1. We wash the cylinder head from dirt and deposits with kerosene or diesel fuel.
2. Remove from the threaded holes of the cylinder block (for head bolts) residual oil and coolant.
3. We clean the mating planes of the head and cylinder block from the remnants of the old gasket, degrease the planes with a solvent.
Warning! Always use a new gasket when installing the cylinder head. Oil must not get on the surface of the gasket
4. We install the guide bushings of the head in the seats of the cylinder block. We lay the gasket on the cylinder block, while the guide bushings must enter the corresponding holes in the gasket.
5. Install the head on the cylinder block. Slightly moving the head from side to side, we ensure that the guide bushings enter the corresponding recesses of the head.
Warning! The cylinder head bolts may only be reused if their length does not exceed 100 mm
6. With a caliper or locksmith's ruler, we measure the length of the bolts. Bolts longer than 100 mm are replaceable.
7. Before installation, dip the threaded part of the bolts into engine oil, and let the oil drain, after waiting about half an hour.
8. We install the bolts of its fastening into the holes of the head. Using a torque wrench, tighten the head mounting bolts in three stages - first with a torque of 20 N·m (2 kgf·m) then turn the bolts 90°and then turn the bolts 90°again. At the same time, we observe the sequence indicated in the photo.
Head bolt tightening sequence
Further assembly of the engine is carried out in the reverse order.