Cylinder Head Assembly: Testing and Inspection

2AZ-FE ENGINE MECHANICAL: CYLINDER HEAD: INSPECTION

INSPECTION

1. INSPECT CYLINDER HEAD FOR WARPAGE

(a) Using a precision straightedge and a feeler gauge, measure the surface that is in contact with the cylinder block and the manifolds for warpage.
Maximum warpage:
0.08 mm (0.0032 in.)
If the warpage is greater than the maximum, replace the cylinder head sub-assembly.
2. INSPECT CYLINDER HEAD FOR CRACKS

(a) Using a dye penetrate, inspect the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
If cracked, replace the cylinder head.
3. INSPECT VALVE SEAT
(a) Apply a light coat of Prussian blue to the valve face.
(b) Lightly press the valve against the seat.
NOTE: Do not turn the valve.

(c) Check the valve face and seat in accordance with the following procedure.
(1) If blue appears 360°around the face, the valve is concentric. If not, replace the valve.
(2) If blue appears 360°around the valve seat, the guide and face are concentric. If not, resurface the valve seat Procedures.
(3) Check that the seat contact is in the middle of the valve face with a width of between 1.0 to 1.4 mm (0.039 to 0.055 in.).
4. INSPECT CAMSHAFT TIMING GEAR ASSEMBLY

(a) Check the lock of the camshaft timing.
(1) Clamp the camshaft in a vise, and confirm that the camshaft timing gear is locked.
NOTE: Be careful not to damage the camshaft.

(b) Release the lock pin.
(1) Cover the 4 oil paths of the cam journal with vinyl tape as shown in the illustration.
HINT: 2 advance side paths are provided in the groove of the camshaft. Plug one of the paths with a rubber piece.
(2) Break through the tape of the advance side path and the retard side path on the opposite side of the groove.

(3) Apply approximately 200 kPa (2.0 kgf/cm2, 28 psi) of air pressure to the paths whose tape was broken in the procedure above.
CAUTION: Some oil spraying will occur. Contain the spray with a shop rag.
(4) Check that the camshaft timing gear revolves in the advance direction when weakening the air pressure of the retard side path.
OK:
Gear rotates in advance direction.
HINT: This operation releases the lock pin for the extreme retard position.
(5) When the camshaft timing gear reaches the extreme advance position, remove the air gun from the retard side path and advance side path, in that order.
NOTE: Do not remove the air gun from the advance side path first. The gear may abruptly shift in the retard direction and break the lock pin.

(c) Check for smooth rotation.
(1) Rotate the camshaft timing gear within its movable range several times, but do not turn it to the extreme retard position. Check that the gear rotates smoothly.
OK:
Gear rotates in advance direction.
NOTE: Do not use an air gun to perform the smooth operation check.

(d) Check the lock in the extreme retard position.
(1) Confirm that the camshaft timing gear is locked at the extreme retard position.
5. INSPECT CAMSHAFT

(a) Inspect the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout:
0.03 mm (0.0012 in.)
If the circle runout is greater than the maximum, replace the camshaft.

(b) Inspect the cam lobes.
(1) Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
46.495 to 46.595 mm (1.8305 to 1.8345 in.)
Minimum cam lobe height:
46.385 mm (1.8262 in.)
If the cam lobe height is less than the minimum, replace the camshaft.

If the journal diameter is not as specified, check the oil clearance.
6. INSPECT NO. 2 CAMSHAFT

(b) Inspect the cam lobes.
(1) Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
45.983 to 46.083 mm (1.8104 to 1.8143 in.)
Minimum cam lobe height:
45.873 mm (1.8060 in.)
If the cam lobe height is less than the minimum, replace the No. 2 camshaft.

If the journal diameter is not as specified, check the oil clearance.
7. INSPECT CAMSHAFT THRUST CLEARANCE

(a) Install the 2 camshafts Installation.
(b) Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance:

Maximum thrust clearance:

- If the thrust clearance is greater than the maximum, replace the cylinder head.
- If damage is found on the camshaft thrust surfaces, replace the camshaft.

8. INSPECT CAMSHAFT OIL CLEARANCE

(a) Clean the 10 bearing caps and camshaft journals.
(b) Place the 2 camshafts on the cylinder head.
(c) Lay a strip of Plastigage across each of the camshaft journals.
(d) Install the 10 bearing caps Installation.
NOTE: Do not turn the camshaft.

(e) Remove the 10 bearing caps Removal and Removal).

(f) Measure the Plastigage at its widest point.
Standard oil clearance:

Maximum oil clearance:

NOTE: Completely remove the Plastigage after the measurement.
If the oil clearance is greater than the maximum, replace the cylinder head sub-assembly or the camshaft.
If the oil clearance on the No. 1 journal is greater than the maximum, choose a new bearing and install it.
Standard cylinder head journal bore diameter:

Standard bearing center wall thickness:

Standard camshaft journal diameter:
35.971 to 35.985 mm (1.4162 to 1.4167 in.)
9. INSPECT VALVE LIFTER

(a) Using a micrometer, measure the lifter diameter.
Standard lifter diameter:
30.966 to 30.976 mm (1.2191 to 1.2195 in.)
If the diameter is not as specified, replace the valve lifter.
10. INSPECT VALVE LIFTER OIL CLEARANCE

(a) Using a caliper gauge, measure the valve lifter bore diameter of the cylinder head.
Standard lifter bore diameter:
31.009 to 31.025 mm (1.2208 to 1.2215 in.)
If the diameter is not as specified, replace the cylinder head sub-assembly.
(b) Subtract the valve lifter diameter measurement from the valve lifter bore diameter measurement.
Standard oil clearance:
0.033 to 0.059 mm (0.0013 to 0.0023 in.)
Maximum oil clearance:
0.079 mm (0.0031 in.)
If the oil clearance is greater than the maximum, replace the valve lifter. If necessary, replace the cylinder head sub-assembly.
11. INSPECT INNER COMPRESSION SPRING

(a) Using vernier calipers, measure the free length of the valve spring.
Standard free length:
4.7 mm (0.185 in.)
If the length is not as specified, replace the inner compression spring.

(b) Using a steel square, measure the deviation of the inner compression spring.
Maximum deviation:
1.6 mm (0.063 in.)
Maximum angle (Reference):
2°
If the deviation is greater than the maximum, replace the inner compression spring.
12. INSPECT INTAKE VALVE

(a) Using vernier calipers, measure the valve overall length.
Standard overall length:
101.71 mm (4.0043 in.)
Minimum overall length:
101.21 mm (3.9846 in.)
If the overall length is less than the minimum, replace the intake valve.

(b) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter:
5.470 to 5.485 mm (0.2154 to 0.2159 in.)
If the diameter is not as specified, replace the intake valve.

(c) Using vernier calipers, measure the valve head margin thickness.
Standard margin thickness:
1.0 mm (0.039 in.)
Minimum margin thickness:
0.50 mm (0.0197 in.)
If the diameter is not as specified, replace the intake valve.
13. INSPECT EXHAUST VALVE

(a) Using vernier calipers, measures the valve overall length.
Standard overall length:
101.15 mm (3.9823 in.)
Minimum overall length:
100.70 mm (3.9646 in.)
If the overall length is less than the minimum, replace the exhaust valve.

(b) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter:
5.465 to 5.480 mm (0.2152 to 0.2158 in.)
If the overall length is less than the minimum, replace the exhaust valve.

(c) Using vernier calipers, measure the valve head margin thickness.
Standard margin thickness:
1.0 mm (0.039 in.)
Minimum margin thickness:
0.50 mm (0.0197 in.)
If the overall length is less than the minimum, replace the exhaust valve.
14. INSPECT INTAKE VALVE GUIDE BUSH

(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Standard bush inside diameter:
5.510 to 5.530 mm (0.2169 to 0.2177 in.)
If the inside diameter is not as specified, replace the intake valve guide bush.
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Standard oil clearance:
0.025 to 0.060 mm (0.0010 to 0.0024 in.)
Maximum oil clearance:
0.08 mm (0.0032 in.)
If the clearance is greater than the maximum, replace the valve and intake guide bush.
15. INSPECT EXHAUST VALVE GUIDE BUSH

(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Standard bush inside diameter:
5.510 to 5.530 mm (0.2169 to 0.2177 in.)
If the inside diameter is not as specified, replace the exhaust valve guide bush.
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Standard oil clearance:
0.030 to 0.065 mm (0.0012 to 0.0026 in.)
Maximum oil clearance:
0.10 mm (0.0039 in.)
If the clearance is greater than the maximum, replace the valve and exhaust valve guide bush.
16. INSPECT CYLINDER HEAD SET BOLT

(a) Using vernier calipers, measure the length of the head bolts from the seat to the end.
Standard bolt length:
161.3 to 162.7 mm (6.350 to 6.406 in.)
Maximum bolt length:
164.2 mm (6.465 in.)
If the bolt length is greater than the maximum, replace the cylinder head set bolt.