- a special template or a wide locksmith's ruler;
- flat feeler set.
Execution sequence
1. We prepare the car for work (see "Preparing the car for maintenance and repair").
2. Remove the cylinder head (see "Cylinder head for 2112 and 21124 engines (16v) - removal and installation", or see "Cylinder head for 2111 and 21114 engines (8v) - removal and installation").
3. We clean the head of the block and the bearing housing from dirt and carbon deposits, wash it from oil deposits, remove carbon deposits from the walls of the combustion chambers with a metal brush.
4. Carefully inspect the block head and bearing housing. They should not have cracks. On the working surfaces of the camshaft bearings, on the bearing housings and on the walls of the seats of the valve lifters, there should be no scoring and traces of metal enveloping.
The guides and valve seats must fit snugly in the body of the head, with no traces of their displacement during timing operation. Valves and their seats must not have cracks or burn marks. We check the backlash of the valves in the guides, the maximum allowable clearance is 0.30 mm.
5. Check the flatness of the head. We carry out the work in two stages.
Comment. The work is shown on the example of a 16-valve engine block head; on an 8-valve engine block head, it is performed similarly.
This requires a special template, but if it is not there, then you can check the lower mating plane of the head with a sufficient degree of accuracy using a wide locksmith's ruler.
With an edge, we apply a ruler diagonally to the plane of the head. We make sure that there is no gap between the edge of the ruler and the plane of the head. The gap can be observed both in the middle part of the plane and along its edges. We measure the gap along both diagonals with a set of flat probes.
The maximum allowable gap is 0.1 mm.
If the gap is greater than the allowable, the head must be milled along the mating plane or replaced.
Warning! The cylinder head of a 16-valve engine should only be replaced complete with a bearing housing.
6. Check the tightness of the block head. To do this, close the window of the coolant supply channel to the thermostat with a plug on the end surface of the block head.
7. We turn the head over and fill its internal cavities for coolant with kerosene.
Comment. The check is shown on the example of an 8-valve engine block head. On a 16-valve engine, it is carried out similarly.
8. Checking the tightness of the valves (see below, "Valves - lapping").