Cylinder Head Assembly: Testing and Inspection
2AZ-FE ENGINE MECHANICAL: CYLINDER HEAD:
INSPECTION
1. INSPECT CYLINDER HEAD FOR FLATNESS
(a) Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder block and the manifolds for warpage.
Maximum warpage:
If the warpage is greater than the maximum, replace the cylinder head.
2. INSPECT CYLINDER HEAD FOR CRACKS
(a) Using a dye penetrate, check the intake ports, exhaust ports and cylinder surface for cracks.
If cracked, replace the cylinder head.
3. INSPECT VALVE SEATS
(a) Apply a light coat of Prussian blue to the valve face.
(b) Lightly press the valve face against the valve seat.
(c) Check the valve face and valve seat according to the following procedure.
(1) If blue appears 360° around the valve face, the valve face is concentric. If not, replace the valve.
(2) If blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.
(3) Check that the valve seat contact is in the middle of the valve face with the width between 1.0 to 1.4 mm (0.039 to 0.055 in.).
4. REPAIR VALVE SEATS
NOTE: Keep the lip free from foreign matter.
(a) If the seating is too high on the valve face, use 30° and 45° cutters to correct the seat.
(b) If the seating is too low on the valve face, use 75° and 45° cutters to correct the seat.
(c) Handrub the valve and valve seat with an abrasive compound.
(d) Check the valve seating position.
5. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Install the camshafts.
(b) Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Specified thrust clearance:
If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.
6. INSPECT CAMSHAFT OIL CLEARANCE
(a) Clean the bearing caps and camshaft journals.
(b) Place the camshafts on the cylinder head.
(c) Lay a strip of plastigage across each of the camshaft journals.
(d) Install the bearing caps.
Bearing cap No.1 - Torque: 30 Nm (301 kgf-cm, 22 ft-lbf)
Bearing cap No.2 - Torque: 30 Nm (301 kgf-cm, 22 ft-lbf)
Bearing cap No.3 - Torque: 9.0 Nm (92 kgf-cm, 80 in-lbf)
NOTE: Do not turn the camshaft.
(e) Remove the bearing caps, and measure the plastigage at its widest point.
Specified oil clearance:
NOTE: Completely remove the plastigage after the inspection.
- If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head.
- If the oil clearance on the camshaft No.1 journal is greater than the maximum, choose a new bearing and install it.
(1) Check the number mark shown in the illustration.
Cylinder head journal bore diameter:
Standard bearing center wall thickness:
Camshaft journal diameter:
35.971 to 35.985 mm (1.4162 to 1.4167 in.)
7. INSPECT INNER COMPRESSION SPRING
(a) Using a vernier caliper, measure the free length of the valve spring.
Free length:
45.7 mm (1.799 in.)
If the free length is not as specified, replace the valve spring.
(b) Using steel squares, measure the deviation of the valve spring.
Maximum deviation:
1.6 mm (0.063 in.)
If the deviation is greater than the maximum, replace the valve spring.
8. INSPECT INTAKE VALVE
(a) Using a vernier caliper, measure the valve's overall length.
Specified overall length:
101.21 to 101.71 mm (3.9846 to 4.0043 in.)
If the overall length is less than the minimum, replace the valve.
(b) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
5.470 to 5.485 mm (0.2154 to 0.2159 in.)
(c) Using a vernier caliper, measure the valve head margin thickness.
Specified margin thickness:
0.50 to 1.45 mm (0.0197 to 0.0571 in.)
If the margin thickness is less than the minimum, replace the valve.
9. INSPECT EXHAUST VALVE
(a) Using a vernier caliper, measure the valve's overall length.
Specified overall length:
100.70 to 101.15 mm (3.9646 to 3.9823 in.)
If the overall length is less than the minimum, replace the valve.
(b) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
5.465 to 5.480 mm (0.2152 to 0.2157 in.)
(c) Using a vernier caliper, measure the valve head margin thickness.
Specified margin thickness:
0.50 to 1.60 mm (0.0197 to 0.0630 in.)
If the margin thickness is less than the minimum, replace the valve.
10. INSPECT INTAKE VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Bushing inside diameter:
5.510 to 5.530 mm (0.2169 to 0.2177 in.)
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Specified oil clearance:
0.025 to 0.080 mm (0.0010 to 0.0031 in.)
If the clearance is greater than the maximum, replace the valve and guide bush.
11. INSPECT EXHAUST VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Bushing inside diameter:
5.510 to 5.530 mm (0.2169 to 0.2177 in.)
(b) Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Specified oil clearance:
0.030 to 0.100 mm (0.0012 to 0.0039 in.)
If the clearance is greater than the maximum, replace the valve and guide bush.
12. INSPECT VALVE LIFTER
(a) Using a micrometer, measure the lifter diameter.
Lifter diameter:
30.966 to 30.976 mm (1.2191 to 1.2195 in.)
(b) Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter:
31.009 to 31.025 mm (1.2208 to 1.2215 in.)
(c) Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Specified oil clearance:
0.033 to 0.070 mm (0.0013 to 0.0028 in.)
If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.