Examination
Thoroughly flush the cylinder block and clean the oil passages. After blowing and drying the cylinder block with compressed air, inspect it. If there are cracks in the bearings or elsewhere in the cylinder block, it must be replaced.
If there is a suspicion that coolant has entered the crankcase, then check the tightness of the cylinder block on a special stand. To do this, by plugging the holes in the cooling jacket of the cylinder block, water at room temperature is injected into it at a pressure of 3 kgf / cm2. Within 2 minutes there should be no leakage of water from the cylinder block.
If oil gets into the coolant, then without complete disassembly of the engine, they check for cracks in the cylinder block in the areas of the oil channels. To do this, drain the coolant, remove the cylinder head, fill the cooling jacket of the cylinder block with water and supply compressed air to the vertical oil channel of the cylinder block, which is located near the first cylinder head bolt (for bolt numbers, see rice. 12). If air bubbles appear in the cooling jacket, replace the cylinder block.
Check the plane of the cylinder block with the head using a ruler and a set of feelers. The ruler is installed along the diagonals of the plane and in the middle in the longitudinal direction and across. If warping exceeds 0.1 mm, the cylinder block is replaced.
Cylinder repair
Check whether the wear of the cylinders exceeds the maximum allowable - 0.15 mm. The cylinder diameter is measured by an inside gauge in four zones at a distance of 5, 15, 45 and 80 mm from the upper plane of the cylinder block both in the longitudinal and transverse directions of the engine. To set the inside gauge to zero, a caliber of type 67.8125.9501 is used for engine 2105 or caliber A.96137 for engines 2101 and 2103. In the area of the upper belt (at a distance of 5 mm from the top plane) Cylinders practically do not wear out. Therefore, by the difference in measurements in the upper and other belts, one can judge the wear of the cylinders.
If the maximum wear of the cylinders exceeds 0.15 mm, then the cylinders are bored to the nearest repair size of the pistons (enlarged by 0.4 or 0.8 mm), leaving an allowance of 0.03 mm for honing. Then the cylinders are honed, maintaining such a diameter that when installing the selected repair piston, the gap between it and the cylinder is 0.06–0.08 mm for the 2105 engine or 0.05–0.07 mm for the 2101 and 2103 engines.