Inspect for flatness.
Using a precision straight edge and feeler gauge, measure the surface contacting cylinder block and the manifolds for warpage.
Flatness of cylinder head gasket surface
Standard : Less than 0.05mm(0.002in.)
[Less than 0.02mm(0.0008in.)/150x150]
Flatness of manifold gasket surface
Standard : Less than 0.03mm(0.001in)/110x110
Inspect for cracks.
Check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head.
Inspect valve stems and valve guides.
Using a caliper gauge, measure the inside diameter of the valve guide.
Valve guide I.D.
Intake / Exhaust : 5.500 ~ 5.512mm (0.216 ~ 0.217in.)
Using a micrometer, measure the diameter of the valve stem.
Valve stem O.D.
Intake : 5.465 ~ 5.480mm (0.2151 ~ 0.2157in.)
Exhaust : 5.458 ~ 5.470mm (0.2149 ~ 0.2153in.)
Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.
Valve stem-to-guide clearance
[Standard]
Intake : 0.020 ~ 0.047mm (0.0008 ~ 0.0018in.)
Exhaust : 0.030 ~ 0.054mm (0.0012 ~ 0.0021in.)
[Limit]
Intake : 0.07mm (0.0027in.)
Exhaust : 0.09mm (0.0035in.)
Inspect valves.
Check the valve is ground to the correct valve face angle.
Check that the surface of the valve for wear.
If the valve face is worn, replace the valve.
Check the valve head margin thickness.
If the margin thickness is less than minimum, replace the valve.
Margin
[Standard]
Intake : 1.56 ~ 1.86mm (0.06142 ~ 0.07323in.)
Exhaust : 1.73 ~ 2.03mm (0.06811 ~ 0.07992in.)
Check the valve length.
Length
Intake : 105.27mm (4.1445in)
Exhaust : 105.50mm (4.1535in)
Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
Inspect valve seats
Check the valve seat for evidence of overheating and improper contact with the valve face.
If the valve seat is worn, replace cylinder head.
Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace cylinder head. 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.
Inspect valve springs.
Using a steel square, measure the out-of-square of the valve spring.
Using vernier calipers, measure the free length of the valve spring.
Valve spring
[Standard]
Free height : 45.5mm (1.7913in.)
Out-of-square : 1.5˚
Inspect MLAs.
Using a micrometer, measure the MLA outside diameter.
MLA O.D.
Intake/Exhaust :
34.964 ~ 34.980mm(1.3765 ~ 1.3771in.)
Using a caliper gauge, measure MLA tappet bore inner diameter of cylinder head.
Tappet bore I.D.
Intake/Exhaust :
35.000 ~ 35.025mm(1.3779 ~ 1.3789in.)
Subtract MLA outside diameter measurement from tappet bore inside diameter measurement.
MLA to tappet bore clearance
[Standard]
Intake/Exhaust : 0.020 ~ 0.061mm(0.0008 ~ 0.0024in.)
[Limit]
Intake/Exhaust : 0.07mm(0.0027in.)
Inspect cam lobes.
Using a micrometer, measure the cam lobe height.
Cam height
[Standard value]
Intake : 47.2mm (1.8582in.)
Exhaust : 45.8mm (1.8031in.)
If the cam lobe height is less than standard, replace the camshaft.
Inspect the camshaft journal clearance.
Clean the bearing caps and camshaft journals.
Place the camshafts on the cylinder head.
Lay a strip of plastigage across each of the camshaft journals.
Install the bearing cap (A) and thrust bearing cap (B) with specified torque. (Refer to Cylinder head in this group)
Tightening torque :
1st step : 5.8N.m (0.6kgf.m, 4.3lb-ft)
2nd step : 9.8 ~ 11.8N.m (1.0 ~ 1.2kgf.m, 7.2 ~ 8.7lb-ft)
Do not turn the camshaft.
Remove the bearing caps.
Measure the plastigage at its widest point.
Bearing oil clearance
[Standard value]
Intake
No.1 journal : 0.020 ~ 0.057mm (0.0008 ~ 0.0022in.)
No.2,3,4 journal : 0.030 ~ 0.067mm (0.0012 ~ 0.0026in.)
Exhaust
No.1 journal : 0.027 ~ 0.057mm (0.0010 ~ 0.0022in.)
No.2,3,4 journal : 0.030 ~ 0.067mm (0.0012 ~ 0.0026in.)
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace cylinder head.
Completely remove the plastigage.
Remove the camshafts.
Inspect the camshaft end play.
Install the camshafts.
Install the bearing cap (A) and thrust bearing cap (B) with specified torque.
Tightening torque :
1st step : 5.8N.m (0.6kgf.m, 4.31lb-ft)
2st step : 9.8N.m (1.0 ~ 1.2kgf.m, 7.2 ~ 8.7lb-ft)
Using a dial indicator, measure the end play while moving the camshaft back and forth.
Camshaft end play
[Standard value] : 0.02 ~ 0.18mm(0.0008 ~ 0.0071in.)
If the end play is greater than maximum, replace the camshaft. If necessary, replace cylinder head.
Remove the camshafts.
Inspect the CVVT assembly.
Check that the CVVT assembly will not turn.
Apply vinyl tape to the retard hole except the one indicated by the arrow in the illustration.
Wrap tape around the tip of the air gun and apply air of approx. 150kpa(1.5kgf/cm², 21psi) to the port of the camshaft.
(Perform this in order to release the lock pin for the maximum delay angle locking.)
To reduce oil splashing during pressurizing with air gun, shield the nozzle tip with a shop rag. Wipe off any splashed oil after checking.
Under the condition of (3), turn the CVVT assembly to the advance angle side (the arrow marked direction in the illustration) with your hand.
Depending on the air pressure, the CVVT assembly will turn to the advance side without applying force by hand.
Except the position where the lock pin meets at the maximum delay angle, let the CVVT assembly turn back and forth and check the movable range and that there is no interference.
Standard: The normal movable range is approximately 30° before the lock pin.
Turn the CVVT assembly with your hand and lock it at the maximum delay angle position (clockwise).
