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Removal and repair of cylinder head
| Fig. 2.249. The cylinder head, valves and valve springs
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Withdrawal Drain the coolant and disconnect the upper radiator hose. Disconnect the duct and the crankcase ventilation hose. Disconnect vacuum, fuel and water hoses. Remove the intake manifold. Disconnect the spark plug high-voltage wires. Pull the protective cap, not the wires themselves. Remove the ignition coil. Remove the timing belt cover. Remove the timing belt and sprockets of camshafts. Remove the protective cover exhaust manifolds and exhaust manifolds themselves. Remove the water pump pulley and valve covers. Remove camshafts. In two or three reception loosen the cylinder head bolts (tool head 12 mm). Remove the cylinder head. Remove the remnants of the old gasket from the mating surfaces of the cylinder head and the block.
NOTE Take measures to ensure to prevent dirt from entering the engine crankcase. |
Cylinder Head Inspection Inspect the cylinder head for cracks, damage and leakage of coolant. If cracks are found, replace the cylinder head. Thoroughly clean the cylinder head from the scale, sludge and remnants of the old sealant and gaskets. Clean oil passage, blow them with compressed air.
| Fig. 2.250. Checking flatness mating surface of the cylinder head
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Check the flatness of the cylinder head mating surfaces in the directions shown in Figure 2.250. Nonflatness mating surface of the cylinder head: Nominal value: less than 0.03 mm. Limit: 0.05 mm.
Checking the valve guides
| Fig. 2.251. Checking the gap between the valve guide and valve stem
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Check the gap between the valve guide and valve stem (several points along the length). If the clearance is more than the limit, replace the valve guide (Fig. 2.251). The gap between the guide and valve stem. Nominal value: inlet valve - 0.02-0.05 mm; outlet valve: 0,035-0,065 mm. Limit: inlet valve - 0.10 mm; exhaust valve - 0.15 mm.
Check valves Check each valve for wear, damage and deformation of the plate and the zone ?�B?� of the valve stem. Replace the valve if necessary. If at the end of ?�A?� valve stem formed dents or present considerable wear, replace the valve.
Check the status of shut-off valve face, restore, if necessary (Fig. 2.252). Replace the valve if the valve disc thickness less than the limit The thickness of the valve plate. Nominal value: The inlet valve - 1.0 mm; Exhaust valve - 1.3 mm. Limit: The inlet valve - 0.5 mm; Exhaust valve - 0.8 mm.
Checking valve springs Check the length of the valve spring in the free state. If the length of the spring is less than the limit, replace the valve spring.
With check-square deviation from the spring axis perpendicular to the supporting surface (perpendicularity). If perpendicularity over the limit, replace the valve spring (Fig. 2.254). Valve spring. Nominal value: length of the spring in a free state - 42.5 mm; Spring length under a load of 21.9 kg - 35.0 mm; the deviation of the axis of the spring (perpendicularity) - 1,5 ?� or less. Limit: length of the spring in a free state - 41.5 mm; Spring length under a load of 21.9 kg - 34.0 mm; the deviation of the axis of the spring (perpendicularity) - 3 ?�.
Restoration of the valve seat Check the valve seat for signs of overheating and uneven contact with the shut-off valve disc facet. If necessary, or restore or replace the valve seat. Before restoring the valve seat check valve guide for wear. If the guide sleeve is worn, replace it with something first, and then restore the valve seat.
Restoration of the valve seat is made special tool (cutters or machine tools). After the restoration of the valve seat and valve seat must be lapped using lapping compound (Fig. 2.255).
Replacing the valve guide With a special tool (mandrel for setting the guide bushing 09221-29000), press out the old valve guide from the cylinder head in the direction of the surface of the gasket.
Ream hole for installation of the cylinder head valve guide corresponding repair size (larger diameter) (Fig. 2.256). With a special tool (mandrel for setting the guide bushing 09221-29000 (A), 09222-22000 (B)), press in the new valve guide. Guide sleeve should embed from the bed of a camshaft. Note the difference in the length guides for the intake and exhaust valves. After installing the valve guide, insert a new valve and check that the gap between the guide sleeve and valve stem corresponds to the nominal value.
After replacing the valve guide, check for correct seating in the valve seat. If necessary, treat with a valve seat (Fig. 2.257).
NOTE Do not set the size of the old guide, always spend a boring head for the next repair size guide. |
Replacing the valve seat
Cut a replaceable valve seat, a residual amount of metal shown in figure 2.258.
| Fig. 2.259. Scheme bore holes in the cylinder head
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Chisel a hole in the cylinder head for the installation of the valve seat corresponding repair size (larger diameter) (Fig. 2.259). Heat the cylinder head to a temperature of about 250 ?� C and press-fit oversize seat in the cylinder head. Grind to a new valve seat using lapping compound. The width of the bevel stop valve seat: intake - 1.1-1.5 mm; Issue - 1.3-1.7 mm.
Assembly Install the valve spring seat.
With a special tool (mandrel to install the valve stem seal 09222-22001) a light blow install the valve stem seal in place (Fig. 2.260).
NOTE The reuse valve stem seals is not allowed. Improper installation of the valve stem seal can lead to oil leakage through the valve guide. |
Lubricate the valve stem with engine oil. Insert the valve into the valve guide. Do not force the passage of the valve stem through the valve stem seal. After installing the valve, check the smoothness of its movement.
| Fig. 2.261. The scheme of installation of the valve spring
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Install the valve spring so that the painted coil spring was located near the spring plate (top), and then install the valve spring plate (Fig. 2.261).
With a special tool (fixture to compress the valve springs 09222-28000 and 09222-28100 adapter) compress valve spring and establish crackers. Before removing the special tool after installing the valve check the reliability of the installation of crackers (Fig. 2.262).
NOTE When compressing the valve spring, take care to not touch the plate spring valve stem seal. |
Clean the gasket plane of the gasket on the cylinder head and cylinder block. Check the identification marks cylinder head gasket technical data.
Install the cylinder head gasket on the engine block with an identification mark up (to the cylinder head) (Fig. 2.263).
NOTE The sealant is not applied to the gasket. |
Tighten the cylinder head bolts to the specified torque in the order shown in Figure 2.264.
| Fig. 2.264. Tightening the bolts of the cylinder head
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When tightening the bolts (tool head 12 mm) using a combined method of tightening (torque + angle tightening angle) (Fig. 2.264).
| Fig. 2.265. Order of a tightening of bolts of the cylinder head
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| Fig. 2.266. Driving resetting bolts of the cylinder head
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The tightening torque of the cylinder head bolts: 25 Nm + (58-62 ?�) + (43-47 ?�) (Fig. 2.266).
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