INSPECTION

PROCEDURE

1. INSPECT CYLINDER HEAD SUB-ASSEMBLY

(a) Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head sub-assembly contacts the cylinder block sub-assembly, intake manifold and exhaust manifold (TWC: Front Catalyst).

Maximum Warpage:

HINT:

If the warpage is more than the maximum, replace the cylinder head sub-assembly.

(b) Using a dye penetrant, check the intake ports, exhaust ports and cylinder head sub-assembly surface for cracks. HINT: If cracks are found, replace the cylinder head sub-assembly.

2. INSPECT COMPRESSION SPRING

(a) Intake Side:

(1) Using a vernier caliper, measure the free length of the compression spring. Standard Free Length: 53.71 mm (2.11 in.) HINT: If the free length is not as specified, replace the compression spring.

(2) Using a steel square, measure the deviation of the compression spring. Maximum Deviation (Reference): 1.0 mm (0.0394 in.) HINT: If the deviation is more than the maximum, replace the compression spring.

*a Deviation *b 37 mm (1.46 in.)

(b) Exhaust Side:

(1) Using a vernier caliper, measure the free length of the compression spring. Standard Free Length: 55.11 mm (2.17 in.) HINT: If the free length is not as specified, replace the compression spring.

(2) Using a steel square, measure the deviation of the compression spring. Maximum Deviation (Reference): 1.0 mm (0.0394 in.) HINT: If the deviation is more than the maximum, replace the compression spring.

*a Deviation *b 38 mm (1.50 in.)

3. INSPECT INTAKE VALVE

(a) Using a micrometer, measure the diameter of the valve stem. Standard Valve Stem Diameter: 5.470 to 5.485 mm (0.215 to 0.216 in.) HINT: If the valve stem diameter is not as specified, check the intake valve guide bush oil clearance.

(b) Using a vernier caliper, measure the valve head margin thickness. Standard Margin Thickness: 1.0 mm (0.0394 in.) Minimum Margin Thickness: 0.5 mm (0.0197 in.) HINT: If the margin thickness is less than the minimum, replace the intake valve.

*a Margin Thickness

(c) Using a vernier caliper, measure the overall length of the intake valve. Standard Overall Length: 104.45 mm (4.11 in.) Minimum Overall Length: 103.95 mm (4.09 in.) HINT: If the overall length is less than the minimum, replace the intake valve.

*a Overall Length

4. INSPECT EXHAUST VALVE

(a) Using a micrometer, measure the diameter of the valve stem. Standard Valve Stem Diameter: 5.465 to 5.480 mm (0.215 to 0.216 in.) HINT: If the valve stem diameter is not as specified, check the exhaust valve guide bush oil clearance.

(b) Using a vernier caliper, measure the valve head margin thickness. Standard Margin Thickness: 1.0 mm (0.0394 in.) Minimum Margin Thickness: 0.5 mm (0.0197 in.) HINT: If the margin thickness is less than the minimum, replace the exhaust valve.

*a Margin Thickness

(c) Using a vernier caliper, measure the overall length of the exhaust valve. Standard Overall Length: 108.7 mm (4.28 in.) Minimum Overall Length: 108.2 mm (4.26 in.) HINT: If the overall length is less than the minimum, replace the exhaust valve.

*a Overall Length

5. INSPECT VALVE GUIDE BUSH OIL CLEARANCE

(a) Using a caliper gauge, measure the inside diameter of the valve guide bush. Standard Valve Guide Bush Inside Diameter: 5.51 to 5.53 mm (0.217 to 0.218 in.)

(b) Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

Standard Oil Clearance:

Maximum Oil Clearance:

6. INSPECT INTAKE VALVE SEAT

(a) Apply a light coat of Prussian blue to the valve face.

(b) Lightly press the valve face against the intake valve seat. NOTICE: Do not rotate the valve while pressing it.

*a Width

(c) Check the valve face and intake valve seat by using the following procedure:

(1) If Prussian blue appears 360° around the entire intake valve face, the valve face is concentric.

HINT:

If the valve face is not concentric, replace the intake valve.

(2) If Prussian blue appears 360° around the entire intake valve seat, the intake valve seat and valve face are concentric.

HINT:

If the valve face is not concentric, replace the cylinder head sub-assembly.

(3) Measure the width of the contact area of the intake valve seat and valve face.

Standard Width:

1.0 to 1.4 mm (0.0394 to 0.0551 in.)

7. INSPECT EXHAUST VALVE SEAT

(a) Apply a light coat of Prussian blue to the valve face.

(b) Lightly press the valve face against the exhaust valve seat. NOTICE: Do not rotate the valve while pressing it.

*a Width

(c) Check the valve face and exhaust valve seat by using the following procedure:

(1) If Prussian blue appears 360° around the entire exhaust valve face, the valve face is concentric.

HINT:

If the valve face is not concentric, replace the exhaust valve.

(2) If Prussian blue appears 360° around the entire exhaust valve seat, the exhaust valve seat and valve face are concentric.

HINT:

If the valve face is not concentric, resurface the exhaust valve seat.

(3) Measure the width of the contact area of the exhaust valve seat and valve face.

Standard Width:

1.3 to 1.7 mm (0.0512 to 0.0669 in.)

8. INSPECT CAMSHAFT THRUST CLEARANCE

(a) Clean the No. 1 camshaft bearing cap, No. 2 camshaft bearing cap, 2 No. 3 camshaft bearing caps, No. 4 camshaft bearing cap, camshaft housing sub-assembly and camshaft journals.

(b) Place the camshaft and No. 2 camshaft on the camshaft housing sub-assembly on the cylinder head sub-assembly.

(c) Install the camshaft bearing caps.

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(d) Install the camshaft housing sub-assembly.

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(e) Using a dial indicator, measure the thrust clearance while moving the camshaft and No. 2 camshaft back and forth. Standard Thrust Clearance: Item Specified Condition Camshaft 0.04 to 0.17 mm (0.00157 to 0.00669 in.) No. 2 Camshaft 0.04 to 0.17 mm (0.00157 to 0.00669 in.) Maximum Thrust Clearance: Item Specified Condition Camshaft 0.22 mm (0.00866 in.) No. 2 Camshaft 0.22 mm (0.00866 in.) HINT: If the thrust clearance is more than the maximum, replace the camshaft housing sub-assembly. If the thrust surface is damaged, replace the camshaft.