Inspection

INSPECTION

CYLINDER HEAD
1. Inspect for flatness.
Using a precision straight edge and feeler gauge, measure the surface the contacting the cylinder block and the manifolds for warpage.

Flatness of cylinder head gasket surface
Standard : Less than 0.03mm (0.0012in)
Limit : 0.05mm (0.0020in)
Flatness of manifold mating surface
Standard : Less than 0.15mm (0.0059in)
Limit : 0.30mm (0.0118in)





2. Inspect for cracks.
Check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head.

VALVE AND VALVE SPRING
1. Inspect the valve stems and valve guides.
(1) Using a caliper gauge, measure the inner diameter of valve guide.

Valve guide inner diameter :
6.000 - 6.015mm (0.2362 - 0.2368in)





(2) Using a micrometer, measure the outer diameter of valve stem.

Valve stem outer diameter
Intake : 5.965 - 5.980mm (0.2348 - 0.2354in)
Exhaust : 5.950 - 5.965mm (0.2343 - 0.2348in)





(3) Subtract the valve stem outer diameter measurement from the valve guide inner diameter measurement.

Valve stem- to-guide clearance
Standard
Intake : 0.020 - 0.050mm (0.0008 - 0.0020in)
Exhaust : 0.035 - 0.065mm (0.0014 - 0.0026in)
Limit
Intake : 0.10mm (0.0039in)
Exhaust : 0.13mm (0.0051in)


If the clearance is greater than maximum, replace the valve and valve guide.
2. Inspect the valves.
(1) Check the valve is ground to the correct valve face angle.
(2) Check the surface of the valve face for damage or wear.
If the valve face is damaged or worn, replace the valve.
(3) Check the valve head margin thickness.
If the margin thickness is less than minimum, replace the valve.

Margin
Standard
Intake : 1.15mm (0.0453in)
Exhaust : 1.35mm (0.0531in)
Limit
Intake : 0.8mm (0.0315in)
Exhaust : 1.0mm (0.0394in)





(4) Check the surface of valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
3. Inspect the valve seats.
(1) Check the valve seat for evidence of overheating and improper contact with the valve face.
Replace the seat if necessary.
(2) Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace it, then recondition the seat.
(3) Recondition the valve seat with a valve seat grinder or cutter. The valve seat contact width should be within specifications and centered on the valve face.




4. Inspect the valve springs.
(1) Using a steel square, measure the out-of-square of valve spring.
(2) Using vernier calipers, measure the free length of valve spring.

Valve spring
Standard
Free height : 48.86mm (1.9236in)
Load : 18.8±0.9kg/39.0mm (41.4±2.0lb/1.5354in)
41.0±1.5kg/30.5mm (90.4±3.3lb/1.2008in)
Out of square : Less than 1.5°
Limit
Out of square : 3°





If the loads is not as specified, replace the valve spring.

CAMSHAFT
1. Inspect the cam lobes.
Using a micrometer, measure the cam lobe height.

Cam height
Intake : 44.518 - 44.718mm (1.7527 - 1.7605in)
Exhaust : 44.418 - 44.618mm (1.7487 - 1.7566in)





If the cam lobe height is less than minimum, replace the camshaft.
2. Inspect the camshaft journal clearance.
(1) Clean the bearing caps and camshaft journals.
(2) Place the camshafts on the cylinder head.
(3) Lay a strip of plastigage across each of the camshaft journal.




(4) Install the bearing caps and tighten the bolts with specified torque.

CAUTION:
Do not turn the camshaft.

(5) Remove the bearing caps.
(6) Measure the plastigage at its widest point.

Bearing oil clearance
Standard : 0.020 - 0.061mm (0.0008 - 0.0024in)
Limit : 0.1mm ( 0.0039in)





If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
(7) Completely remove the plastigage.
(8) Remove the camshafts.
3. Inspect the camshaft end play.
(1) Install the camshafts.
(2) Using a dial indicator, measure the end play while moving the camshaft back and forth.

Camshaft end play
Standard : 0.1 - 0.2mm (0.0039 - 0.0079in)





If the end play is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
(3) Remove the camshafts.

CVVT(Continuous Variable Valve Timing) ASSEMBLY
1. Inspect the CVVT (Continuous Variable Valve Timing) assembly.
(1) Check that the CVVT (Continuous Variable Valve Timing) assembly will not turn.
(2) Apply vinyl tape to all the parts except the one indicated by the arrow in the illustration.




(3) To release the CVVT lock pin, wrap some tape around the tip of an air pressure adapter and apply low air pressure(about 14 psi) to the exposed camshaft port.

NOTE:
Wrap a shop towel or rag around the CVVT because residual oil may leak out of the unit when applying air pressure.

(4) With low air pressure applied, turn the CVVT to the ADVANCE direction as indicated in the illustration.
A. With the low air pressure applied, the CVVT should turn to the ADVANCE side.
B. If too much air leaks when applying the low air pressure, the CVVT lock pin may not release and the CVVT may not turn.




(5) Allow the CVVT assembly to move in the ADVANCE and DELAY directions to ensure there is no binding and that it moves freely.

Standard : Movable smoothly in the range about 20°


(6) Turn the CVVT by hand and make sure it locks in the maximum delay angle position.