Disassembly
1. Using a special tool in the sequence shown in the figure, remove the cylinder head bolts in 2-3 passes.
2. Using a special tool, compress the valve spring and remove the crackers from the valve stem. Slowly release the spring compressor and remove the spring cap, valve spring, spring seat and valve from the cylinder head.
Note. Have numbered plastic bags or containers ready to store the valves.
3. Use pliers to remove the oil deflector cap.
Note. Do not reuse the oil seal.
Examination
Cylinder head
1. Inspect the cylinder head for damage, cracks, oil and coolant leaks. If necessary, replace the cylinder head.
2. Remove scale, sealant and carbon deposits. Blow out the lubrication channels with compressed air. With a metal ruler and feeler gauge in six directions A, B... check the flatness of the cylinder head.
Regrind the cylinder head if necessary.
- Flatness standard deviation: less than 0.03mm
- Maximum allowable deviation from flatness: less than 0.20 mm
Valve
1. Clean the valve with a wire brush.
2. Inspect each valve for wear, damage, and deformation in the area «IN» and, if necessary, repair or replace it.
If the butt «A» rod is corroded or worn, restore the chamfers as necessary. This recovery should be limited to minimal metal removal. Also check the thickness of the cylindrical part of the valve head.
Nominal thickness of the cylindrical part of the valve head, mm
- intake valves: 1.1
- exhaust valves: 1.3
Minimum allowable thickness of the cylindrical part of the valve head, mm
- intake valves: 0.8
- exhaust valves: 1.0
Valve spring
1. Inspect each valve spring for cracks or damage. Measure the free length of the spring.
2. Install the spring on a flat horizontal surface and measure the deviation of the top of the spring from the vertical plane.
- Spring length without load: 44mm
- Spring length under load 21.6 kg: 35.0 mm
- Spring length under load 41.5 kg: 27.2 mm
- Deviation of the spring axis from the vertical plane: no more than 1.5°
- Maximum permissible reduction in the length of the spring without load: -1 mm
- Maximum permissible deviation of the spring axis from the vertical plane: no more than 4°
Valve guides
Check clearance between valve stem and valve guide. If the clearance exceeds the limit, replace the valve guide with an oversized bushing.
Nominal clearance between guide sleeve and valve stem, mm:
- intake valves: 0.03–0.06
- exhaust valves: 0.05–0.08
Maximum allowable gap between the guide sleeve and the valve stem, mm:
- intake valves: 0.1
- exhaust valves: 0.15
Valve seat
Check the valve seat for overheating and damage to the seat in contact with the valve disc. Repair or replace the valve seat if necessary.
Before machining the valve seat, check the valve guide for wear. If the valve guide is worn, replace it and grind the valve seat with a cutter, keeping the bevel width and centering of the valve seat and valve guide tight. After grinding, lap the valve against the seat using lapping paste.
Valve seat replacement
1. Any valve seat insert worn to the limit must be replaced at room temperature by shearing the wall as shown.
2. After removing the old valve seat, it is necessary to bore out the seat for the oversized valve seat. Dimensions for processing are shown in the table.
3. Heat the cylinder head to 250°C and press in a new oversize valve seat. The valve seat must be at room temperature when pressed in. After installing a new valve seat, it is necessary to process its working chamfer.
4. Lappe the valve to the new seat using lapping paste.
The width of the working chamfer of the valve seat, mm:
- intake valves: 0.8–1.2
- exhaust valves: 1.3–1.7
Valve Guide Replacement
1. Using a guide bushing press tool and a press, press the valve bushing out of the cylinder head towards the cylinder block.
2. Using tool 09221-22000 A/B, press the valve guide out of the cylinder head towards the cylinder block.
3. Expand the hole in the cylinder head to install the oversized bushing.
4. Use the valve guide installer 09221-22000 A/B to press the bushing on the top side of the cylinder head.
5. After pressing in the valve guides, insert the new valves and check the clearance between its stem and guide bush.
6. After replacing the guide sleeve, check the correct position of the valve in the seat. Sand the valve seat if necessary.
Oversized valve guide
Assembly
Note.
- 1) Clean all parts before installation.
- 2) Apply a thin coat of engine oil to all sliding surfaces.
1. Establish basic plates of springs.
With light blows of a hammer on the mandrel of tool 09222-22001, press the oil seals onto the guide bushings.
Note.
- Do not reuse old oil seals.
- Incorrect installation of the valve stem seal adversely affects its sealing lip due to eccentricity and causes engine oil to leak through the valve guides.
2. Lubricate the valve stem with engine oil and install the valve. When installing the valve, do not apply much force so as not to damage the oil seal cap. Check for smooth valve movement.
3. Establish springs and plates of springs. The springs must be installed with the side covered with enamel towards the plate.
4. Use the special tool 09222–28000, 09222–28100 to compress the spring. Install crackers and remove the special device for spring compression.
Note. When compressing the spring, make sure the slinger cap is not pinched by the spring compressor.
Oversized valve seat insert
Description | size mark | Saddle height, mm | Diameter of a nest in a head of cylinders, mm |
Inlet valve seat increased by 0.3 mm | 30 | 5,1–5,3 | 30,700–30,721 |
Inlet valve seat increased by 0.6 mm | 60 | 5,4–5,6 | 31,000–31,021 |
Exhaust valve seat increased by 0.3 mm | 30 | 6,2–6,4 | 27,300–27,321 |
Exhaust valve seat increased by 0.6 mm | 60 | 6,5–6,7 | 27,600–27,621 |
5. Clean all mating surfaces of the cylinder block and cylinder head.
6. Check up presence of marking on a laying of a head of cylinders.
7. Install a new cylinder head gasket with the marked surface toward the cylinder head.
8. In the sequence shown in the figure, tighten the cylinder head bolts.
Tightening torques for cylinder head bolts:
- 1.6 l engine: 30 Nm + turn 90°+ loosen all bolts + 30 Nm + turn 90°
- 1.5 l engine: 35 Nm + 90°turn + loosen all bolts + 35 Nm + 90°turn