Cylinder Head Assembly: Service and Repair
Cylinder Head AssemblyREMOVAL
1) Remove the V-belt.
2) Remove the crankshaft pulley.
3) Remove the belt cover.
4) Remove the timing belt assembly.
5) Remove the, camshaft sprocket.
6) Remove the intake manifold.
7) Remove the bolt which installs the A/C compressor bracket on cylinder head.
8) Remove the camshaft.
9) Remove the cylinder head bolts in alphabetical sequence shown in the figure.
CAUTION: Leave bolts (A) and (D) engaged by three or four threads to prevent the cylinder head from falling.
10) While tapping the cylinder head with a plastic hammer, separate it from cylinder block.
Remove the bolts (A) and (D) to remove the cylinder head.
11) Remove the cylinder head gasket.
CAUTION: Do not scratch the mating surface of cylinder head and cylinder block.
12) Similarly, remove the right side cylinder head.
INSTALLATION
1) Install the cylinder head and gaskets on cylinder block.
CAUTION:
- Use new cylinder head gaskets.
- Be careful not to scratch the mating surface of cylinder head and cylinder block.
2) Tighten the cylinder head bolts.
a) Apply a coat of engine oil to washers and bolt threads.
b) Tighten all bolts to 29 Nm (3.0 kgf-m, 22 ft. lbs.) in alphabetical sequence.
c) Retighten all bolts to 69 Nm (7.0 kgf-m, 51 ft. lbs.) in alphabetical sequence.
d) Back off all bolts by 180° first, then back them off a further 180°, in the reverse sequence they were tightened.
e) Tighten all bolts to 39 Nm (4.0 kgf-m, 29 ft. lbs.) in alphabetical sequence.
f) Tighten all bolts 80 - 90° in alphabetical sequence.
g) Tighten all bolts a further 40 - 45° in alphabetical sequence.
NOTE: Do not tighten bolts for more than 45°.
h) Tighten bolt (A) and (B) a further 40 - 45°.
NOTE: Make sure the sum of retightening angles in previous steps has not exceeded 90°.
3) Install the camshaft.
4) Install the A/C compressor bracket on cylinder head.
5) Install the intake manifold.
6) Install the camshaft sprocket.
7) Install the timing belt assembly.
8) Install the belt cover.
9) Install the crankshaft pulley.
10) Install the V-belt.
DISASSEMBLY
1) Remove the valve shims and valve lifters.
2) Compress the valve spring and remove the valve spring retainer key. Remove each valve and valve spring.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499718000 VALVE SPRING REMOVER
CAUTION:
- Keep the removed parts in order for re-installing in their original positions.
- Mark each valve to prevent confusion.
- Use extreme care not to damage the lips of the intake valve oil seals and exhaust valve oil
ASSEMBLY
1) Installation of valve spring and valve:
a) Coat the stem of each valve with engine oil and insert the valve into valve guide.
CAUTION: When inserting the valve into valve guide, use special care not to damage the oil seal lip.
b) Set the cylinder head on ST1.
c) Install the valve spring and retainer using ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499718000 VALVE SPRING REMOVER
CAUTION: Be sure to install the valve springs with their close-coiled end facing the seat on the cylinder head.
d) Compress the valve spring and fit the valve spring retainer key.
e) After installing, tap the valve spring retainers lightly with wooden hammer for better seating.
2) Apply oil to the surface of the valve lifter and valve shim.
3) Install the valve lifter and valve shim.
INSPECTION
CYLINDER HEAD
a) Make sure that no crack or other damage exists. In addition to visual inspection, inspect the important areas by means of red check.
b) Measure the warping of the cylinder head surface that mates with crankcase by using a straight edge (A) and thickness gauge (B).
If the warping exceeds 0.05 mm (0.0020 inch), regrind the surface with a surface grinder.
Warping limit: 0.05 mm (0.0020 inch)
Grinding limit: 0.3mm (0.012inch)
Standard height of cylinder head: 127.5 mm (5.02 inch)
CAUTION: Uneven torque for the cylinder head nuts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly.
VALVE SEAT
Inspect the intake and exhaust valve seats, and correct the contact surfaces with valve seat cutter if they are defective or when valve guides are replaced.
Valve seat width: W
Intake
Standard 1.0 mm (0.039 inch)
Limit 1.7 mm (0.067 inch)
Exhaust
Standard 1.5 mm (0.059 inch)
Limit 2.2 mm (0.087 inch)
VALVE GUIDE
a) Check the clearance between valve guide and stem. The clearance can be checked by measuring the outside diameter of valve stem and the inside diameter of valve guide with outside and inside micrometers respectively.
Clearance between the valve guide and valve stem:
Standard
Intake 0.030 - 0.057 mm (0.0012 - 0.0022 inch)
Exhaust 0.040 - 0.067 mm (0.0016 - 0.0026 inch)
Limit 0.15 mm (0..0059 inch)
b) If the clearance between valve guide and stem exceeds the limit, replace the valve guide or valve itself whichever shows greater amount of wear. See the following procedure for valve guide replacement.
Valve guide inner diameter: 6.000 - 6.012 mm (0.2362 - 0.2367 inch)
Valve stem outer diameters:
Intake 5.955 - 5.970 mm (0.2362 - 0.2367 inch)
Exhaust 5.945 - 5.960 mm (0.2341 - 0.2346 inch)
1) Place the cylinder head on ST1 with the combustion chamber upward so that valve guides enter the holes in ST1.
2) Insert the ST2 into valve guide and press it down to remove the valve guide.
ST1 498267600 CYLINDER HEAD TABLE
ST2 499767200VALVE GUIDE REMOVER
3) Turn the cylinder head upside down and place ST as shown in the figure.
ST 18251AA020 VALVE GUIDE ADJUSTER
4) Before installing a new valve guide, make sure that neither scratches nor damages exist on the inside surface of the valve guide holes in cylinder head.
5) Put a new valve guide, coated with sufficient oil, in cylinder, and insert ST1 into valve guide. Press in until the valve guide upper end is flush with the upper surface of ST2.
ST1 499767200 VALVE GUIDE REMOVER
ST2 18251AA020 VALVE GUIDE ADJUSTER
6) Check the valve guide protrusion.
Valve guide protrusion: L 15.8 - 16.2 mm (0.622 - 0.638 inch)
g) Ream the inside of valve guide with ST. Gently rotate the reamer clockwise while pressing it lightly into the valve guide, and return it also rotating clockwise. After reaming, clean the valve guide to remove chips.
ST 499767400 VALVE GUIDE REAMER
CAUTION:
- Apply engine oil to the reamer when reaming.
- If the inner surface of the valve guide is torn, the edge of the reamer should be slightly ground with an oil stone.
- If the inner surface of the valve guide be comes lustrous and the reamer does not chips, use a new reamer or remedy the reamer.
8) Recheck the contact condition between valve and valve seat after replacing the valve guide.
INTAKE AND EXHAUST VALVE
a) Inspect the flange and stem of valve, and replace if damaged, worn, or deformed, or if "H" is less than the specified limit.
H:
Intake
Standard 1.2 mm (0.047 inch)
Limit 0.8 mm (0.031 inch)
Exhaust
Standard 1.5 mm (0.059 inch)
Limit 0.8 mm (0.031 inch)
Valve overall length:
Intake 104.4 mm (4.110 inch)
Exhaust 104.7 mm (4.122 inch)
b) Put a small amount of grinding compound on the seat surface and lap the valve and seat surface. Install a new intake valve oil seal after lapping.
VALVE SPRINGS
a) Check the valve springs for damage, free length, and tension. Replace the valve spring if it is not within specifications presented in the table.
b) To measure the squareness of the valve spring, stand the spring on a surface plate and measure its deflection at the top using a try square.
INTAKE AND EXHAUST VALVE OIL SEAL
Replace the oil seal with a new one, if the lip is damaged or spring out of place, or when the surfaces of intake valve and valve seat are reconditioned or intake valve guide is replaced.
a) Place the cylinder head on ST1.
b) Press in the oil seal to the specified dimension indicated in the figure by using ST2.
ST1 498267600 CYLINDER HEAD TABLE
ST2 498857100 VALVE GUIDE REMOVER
CAUTION:
- Apply engine oil to oil seal before force-fitting.
- Differentiate between the intake valve oil seal and exhaust valve oil seal by noting their difference in color.
Color of rubber part:
Intake [Black]
Exhaust [Brown]
Color of spring part:
Intake [Silver]
Exhaust [Silver]
VALVE LIFTER
a) Check the valve lifter visually.
b) Measure the outer diameter of valve lifter.
Outer diameter: 34.959 - 34.975 mm (1.3763 - 1.3770 inch)
c) Measure the inner diameter of valve lifter mating part on cylinder head.
Inner diameter: 34.994 - 35.016 mm (1.3777 - 1.3786 inch)
CAUTION: If difference between outer diameter of valve lifter and inner diameter of valve lifter mating part is over the limit, replace the cylinder head.
Standard: 0.019 - 0.057 mm (0.0007 - 0.0022 inch)
Limit: 0.100 mm (0.0039 inch)