Cylinder Head
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, 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 fragments from the gasket 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 (0.0012 inch)
Service limit 0.05 mm (0.002 inch)
Valve Guides
Check the valve stem-to-guide clearance. If the clearance exceeds the service limit, replace the valve guide with anew oversize guide.
Valve stem-to-guide clearance
Standard value
Intake 0.02 - 0.05 mm (0.0009 - 0.0020 inch)
Exhaust 0.035 - 0.065 mm (0.0014 - 0.0026 inch)
Service limit
Intake 0.10 mm (0.0039 inch)
Exhaust 0.15 mm (0.0059 inch)
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 auto-lash 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°
Reconditioning Valve Seat
1. Before reconditioning, check the valve guide for wear. Replace worn guide if necessary, 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.
Replacing Valve Guide
1. Using the Special tool (09222-32200), press down 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)) press-fit the valve guide. The valve guide must be press-fitted 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 proper valve face to valve seat contact.
NOTE: Do not install a valve guide of the same size again.
Replacing Valve Seat Insert
1. Cut away the inner face of the valve seat to reduce thickness.
2. Adjust the press fit diameter of the valve seat on the cylinder head side so that it can match the diameter of the oversize valve seat.
Valve Seat Insert Oversizes
3. Heat the cylinder head to about 250°C (480°F) and press an oversize seat insert fit for 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 1.1 - 1.5 mm (0.043 - 0.059 inch)
Exhaust 1.3 - 1.7 mm (0.051 - 0.067 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 to have the identification mark towards the cylinder head.
NOTE: Do not apply sealant to these surfaces.
Cylinder Head Bolt Tightening Sequence:
9. Torque the cylinder head bolts in the sequence shown in the illustration.
1 of 2
2 of 2
10. Install the cylinder head bolts. Starting at top center, tighten all cylinder head bolts in sequence as shown in illustration. Repeat the procedures, tightening all cylinder head bolt to the specified torque again.
Tightening procedure.
1) Tighten all bolts (1-8): 25 Nm (250 kg-cm, 18 ft. lbs.)
2) Tighten all bolts (1-8): 58° - 62° of a turn
3) Tighten all bolts (1-8): 43° - 47° of a turn