Removal and Installation
DISASSEMBLY
1. Drain the coolant and disconnect the upper radiator hose.
2. Remove the breather hose and air-intake hose.
3. Remove the vacuum hose, fuel hose and coolant hose.
4. Remove the intake manifold.
5. Remove the cables from the spark plugs. The cables should be removed by holding the boot portion.
6. Remove the ignition coil.
7. Remove the upper and lower timing belt cover.
8. Remove the timing belt and camshaft sprockets.
9. Remove the heat protector and exhaust manifold assembly.
10. Remove the coolant pump pulley and head cover.
11. Remove the intake and exhaust camshaft.
12. Remove the cylinder head assembly. The cylinder head bolts should be removed by using S 12 mm socket, in the sequence as shown in the illustration in two or three steps.
13. Remove the gasket pieces from the cylinder block top surface and cylinder head bottom surface.
NOTE: Make sure that the gasket pieces do not fall in the engine.
INSPECTION
Cylinder Head
1. Remove scale, sealing compound and carbon deposits completely. After cleaning oil passages, apply compressed air to make certain that the passages are not clogged.
2. Visually check the cylinder head for cracks, damage or water leakage.
3. Check the cylinder head gasket surface for flatness with a straight edge and feeler as shown in illustration.
Cylinder head flatness:
Standard dimension: max. 0.03 mm (0.0059 inch)
Service limit: 0.20 mm (0.008 inch)
Valve Guides
Check the valve stem-to-guide clearance. If the clearance exceeds the service limit, replace the valve guide with a new oversize guide.
Valve
1. Replace the valve stem if it is worn (stepped, worn or damaged). Also replace it if the stem end (the surface contacting the autoclaves adjuster) is recessed.
2. Check the valve face contact area, and recondition or replace as necessary.
3. Replace the valve if the width of the margin (thickness of the valve head) is less than the minimum specified.
Valve margin
Standard value:
Intake side: 1.0 mm (0.0394 inch)
Exhaust side: 1.3 mm (0.0512 inch)
Service limit:
Intake side: 0.5 mm (0.0197 inch)
Exhaust side: 0.8 mm (0.0315 inch)
Valve Springs
1. Check free height of each valve spring and replace if necessary.
2. Using a square, test squareness of each valve spring. If spring is excessively out of square, replace it.
Valve spring:
Standard value:
Free height: 42.5 mm (1.6732 inch)
Load: 21.9 kg/35 mm (49 lbs/1.3780 inch)
Out of squareness: Max. 1.5°
Service limit:
Free height: 41.5 mm (1.6339 inch)
Load: 21.9 kg/34 mm (49 lbs/1.3386 inch)
Out of squareness: Max. 3°
Valve Seat Reconditioning
1. Before reconditioning, check the valve guide for wear. Replace if necessary, worn guide, and then recondition the the valve seat.
2. To recondition the valve seat, use the Valve Seat Cutter and Pilot.
3. After reconditioning, the valve and valve seat should be lapped lightly with a lapping compound.
Valve Guide Replacement
1. Using the Special tool (09222-32200), press out the old valve guide toward the bottom of cylinder head.
2. Recondition the valve guide hole so that it matches the newly press-fit oversize valve guide.
Valve Guide Insert Oversizes
3. Using the special tool (09221-29000(A), 09221-22000(B)) presift the valve guide. The valve guide must be press-fit from the upper side of the cylinder head. Keep in mind that the valve guides are different in length.
4. After the valve guide is press-fit, insert a new valve and check for proper clearance.
5. After the valve guide has been replaced, check for proper valve face to valve seat contact.
NOTE: Do not re-install a valve guide of the same size.
Valve Seat Insert Replacement
1. Cut away the inner face of the valve seat to reduce thickness, and remove.
2. Adjust the press fit diameter of the valve seat on the cylinder head side so that it matches the diameter of the oversize valve seat.
3. Heat the cylinder head to about 250°C (480°F) and press in an oversize seat insert fit to the insert bore in the cylinder head at normal, temperature.
4. Treat the valve seat in the way shown in the illustration.
5. Use the lapping compound, and lap the valve.
Valve seat contact width:
Intake: 0.9-1.3 mm (0.035-0.051 inch)
Exhaust: 0.9-1.3 mm (0.035-0.051 inch)
INSTALLATION
1. Install the spring seats.
2. Using the special tool (09222-22001), lightly tap the seal into place. The seal is installed in the specified position, using the special tool.
NOTE:
- Do not reuse old valve stem seals.
- Incorrect installation of the seal could result in oil leakage down the valve guides.
3. Apply engine oil to each valve. Insert valves into guides.
Avoid forcing the valve into the seal.
After installing the valve, check that it moves smoothly.
4. Valve springs should be installed with the enamel coated side toward the valve spring retainer.
5. Using the special tool (09222-28000), compress the spring and install the retainer locks. After installation of the valves, make certain that the retainer locks are correctly in place before releasing the valve spring compressor.
NOTE: When the spring is compressed, check that the valve stem seal is not pressed against the bottom of retainer.
6. Clean both gasket surfaces of the cylinder head and cylinder block.
7. Verify the identification marks on the cylinder head gasket.
8. Position the gasket surface with the identification mark towards the cylinder head.
NOTE: Do not apply sealant to these surfaces.
9. Torque the cylinder head bolts in the sequence shown in the illustration with the 12 mm socket and a torque wrench.
10. Install the cylinder head bolts. Starting at top center, tighten all cylinder head bolts in sequence as shown in illustration, using 12 mm socket. Repeat the procedure, retightening all cylinder head bolt to the specified torque.
Tightening procedure.
1. Tighten all bolts (1-8): 25 Nm (250 kg.cm, 8 ft. lbs.)
2. Tighten all bolts (1-8): 60°-64° of a turn
3. Tighten all bolts (1-8): 45°-49° of a turn