Withdrawal
Remove the cylinder head, toothed belt pulleys, front cover, flywheel, pistons and crankshaft.
Examination
Cylinder block
1. Visually inspect the cylinder block for scoring and rust. At the same time, check for cracks and other defects. If there are defects, repair the unit or replace it.
2. Using the indicator, measure the diameter of the cylinders at three levels in mutually perpendicular directions A and B.
- Level 1: The location of the #1 piston ring when the piston is at top dead center.
- Level 2: Center of the cylinder
- Level 3: The bottom of the cylinder
3. If the cylinders are excessively out-of-round or taper, and the cylinder bore is severely worn or raised, the cylinder block should be bored and honed, after which oversized pistons and piston rings should be installed.
Rated value:
- Cylinder diameter - 80.60-80.63 mm
- Out-of-roundness or taper of the cylinder - Max. 0.01mm
4. If the top of the cylinder is worn with steps, cut them off with a reamer.
5. Oversized pistons are available in four sizes.
Piston size and marking, mm
- 0,25 O.S — 0,25
- 0,50 O.S — 0,50
- 0,75 O.S — 0,75
- 1,00 O.S — 1,00
6. When reboring cylinders to larger sizes, assume a specific clearance between the oversized piston and cylinder and ensure that all pistons used are the same size. The standard measurement of the outer diameter of the piston is taken at a distance of 2 mm from the edge of the piston skirt on the pressure-receiving surfaces.
- The gap between the piston and the cylinder mirror is 0.01-0.03 mm
7. Check for damage and cracks.
8. Check top surface for flatness. If there is excessive flatness, grind to the minimum limit or replace the block.
Rated value:
- Non-flatness of the upper surface of the block - Max. 0.05 mm
- Overall height - 290 mm
Limit values:
- Non-flatness of the upper surface of the block - 0.1 mm
- Overall height - 0.2 mm
Warning. The upper surface of the cylinder block should be ground to within -0.2 mm, as well as the lower surface of the cylinder head.
Cylinder boring
1. The oversized pistons used should be determined based on the largest cylinder size.
Size | Identification label |
0.25mmOS | 0.25 |
0.50 mmOS | 0.50 |
0.75mm OS | 0.75 |
1.00 mmOS | 1.00 |
Note. The dimension mark is applied to the piston head.
2. Measure the outside diameter of the pistons being used.
3. Based on the results of measuring the outer diameter of the piston, calculate the diameter of the cylinder after machining.
Cylinder diameter after boring - piston outer diameter + (0,01—0,03) mm (clearance between piston and cylinder bore) - 0.02 mm (allowable honing limit).
4. Rebore each cylinder to the calculated size.
Warning. To prevent deformation of the cylinder block due to an increase in temperature during honing, bore the cylinders in the following order: 2-4-1-3.
5. After honing the cylinders, bring them to the required size (piston outer diameter + clearance between piston and cylinder bore).
Note. When boring cylinders, bring all four cylinders to the same size. Do not bore only one cylinder to a larger size.
Assembly
1. Install the following parts using the instructions given in the relevant paragraphs.
- 1) Crankshaft.
- 2) Flywheel
- 3) Pistons.
- 4) Cylinder head.
- 5) toothed belt pulleys.
- 6) Front cover.
Oil pressure sensor
1. If the oil pressure warning lamp lights up when the ignition is turned on and turns off when the engine is started and is idling, then everything is in order. If the oil pressure warning lamp does not come on when the ignition is turned on, check the sensor, lamp, and wiring.
2. If there is an electric current when the ignition is turned on and it is absent when the engine is idling, the sensor is in order.
If the sensor is OK, check the lamp and electrical wiring.
3. Using a special tool (09260— 32000), tighten the sensor to the required torque.
Note. Do not overtighten the oil pressure sensor
- Oil pressure sensor response pressure - 14.71-29.42 kPa
- Tightening torque: Oil pressure sensor - 8-12 Nm
Examination
1. Using an ohmmeter, check the electrical conductivity between the terminal and the sensor housing. If there is no continuity, replace the sensor.
2. Check the presence of electrical conductivity between the terminal and the sensor body when introducing a thin wire into it. If there is electrical conductivity even when pressed with a wire, replace the sensor.
3. The absence of electrical conductivity when vacuum is applied through the oil hole indicates normal operation of the sensor. Make sure there is no air leakage. The presence of air leakage indicates that the diaphragm is torn. Replace sensor.