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 0.05mm (0.0019in.) for total area
Less than 0.02mm (0.0007in.) for a section of 100mm (3.9370in.) X 100mm (3.9370in.)
Flatness of manifold mounting surface (Intake/Exhaust)
Standard : Less than 0.10mm (0.0039in.)
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 inner diameter
Intake / Exhaust : 5.500 ~ 5.512mm (0.21654 ~ 0.21701in.)
Using a micrometer, measure the diameter of the valve stem.
Valve stem outer diameter
Intake : 5.465 ~ 5.480mm (0.21516 ~ 0.21575in.)
Exhaust : 5.458 ~ 5.470mm (0.214988 ~ 0.21535in.)
Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.
Valve stem-to-guide clearance
[Standard]
Intake : 0.020 ~ 0.047mm (0.00078 ~ 0.00185in.)
Exhaust : 0.030 ~ 0.054mm (0.00118 ~ 0.00212in.)
[Limit]
Intake : 0.070mm (0.00275in.)
Exhaust : 0.090mm (0.00354in.)
If the clearance is greater than maximum, replace the valve or cylinder head.
Inspect the 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.
Valve head thickness (Margin)
[Standard]
Intake : 1.02mm(0.0401in.)
Exhaust : 1.09mm(0.0429in.)
If the margin thickness is less than minimum, replace the valve.
Check the valve length.
Valve length
[Standard]
Intake : 113.18mm(4.4559in.)
Exhaust : 105.79 mm(4.1650 in.)
[Limit]
Intake : 112.93mm(4.4461in.)
Exhaust : 105.59m(4.1571in.)
Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
Inspect the valve seats and the valve guides.
Check the valve seat for evidence of overheating and improper contact with the valve face. If the valve seat is worn, replace the cylinder head.
Check the valve guide for wear. If the valve guide is worn, replace the cylinder head.
Inspect the valve springs.
Using a steel square, measure the out-of-square of the valve spring.
Using a vernier calipers, measure the free length of the valve spring.
If the free length is not as specified, replace the valve spring.
Valve spring
[Standard]
Free height : 47.44mm (1.8677in.)
Out-of-square : Less than 1.5°
Inspect the MLA.
Using a micrometer, measure the MLA outside diameter.
MLA outer diameter :
31.964 ~ 31.980mm (1.2584 ~ 1.2590in.)
Using a caliper gauge, measure MLA tappet bore inner diameter of cylinder head.
Tappet bore inner diameter :
32.000 ~ 32.025mm (1.2598 ~ 1.2608in.)
Subtract MLA outside diameter measurement from tappet bore inside diameter measurement.
MLA to tappet bore clearance
[Standard] : 0.020 ~ 0.061mm (0.00078 ~ 0.00240in.)
[Limit] : 0.070mm (0.00275in.)
Inspect the cam lobes.
Using a micrometer, measure the cam lobe height.
If the cam lobe height is less than standard, replace the camshaft.
Cam height
[Standard value]
Intake : 44.10 ~ 44.30mm (1.7362 ~ 1.7440in.)
Exhaust : 44.90 ~ 45.10mm (1.7677 ~ 1.7756in.)
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 journal.
Install the bearing caps.
Do not turn the camshaft.
Remove the bearing caps.
Measure the plastigage at its widest point.
Bearing oil clearance
[Standard value]
Intake :
No.1 : 0.022 ~ 0.057mm (0.00087 ~ 0.00224in.)
No.2, 3, 4, 5 : 0.030~0.067mm (0.00118 ~ 0.00264 in.)
Exhaust:
No.1 : 0 ~ 0.032mm (0 ~ 0.00126in.)
No.2, 3, 4, 5 : 0.030~0.067mm (0.00118 ~ 0.00264 in.)
[Limit]
Intake:
No.1 : 0.090mm (0.00354in.)
No.2, 3, 4, 5 : 0.120mm (0.00472in.)
Exhaust :
No.1 : 0.090mm (0.00354in.)
No.2, 3, 4, 5 : 0.120mm (0.00472in.)
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.
Using a dial indicator, measure the end play while moving the camshaft back and forth.
Camshaft end play
[Standard value] : 0.04 ~ 0.16mm (0.0016 ~ 0.0063in.)
[Limit] : 0.20mm (0.0078in.)
If the end play is greater than maximum, replace the camshaft. If necessary, replace cylinder head.
Remove the camshafts.
Check the cylinder head bore mark.
Class | Mark | Exhaust No.1 Inside Diameter Of Cylinder Head Bore |
a | A | 40.000 ~ 40.008mm (1.57480 ~ 1.5751in.) |
b | B | 40.008 ~ 40.016mm (1.57511 ~ 1.57543in.) |
c | C | 40.016 ~ 40.021mm (1.57543 ~ 1.57563in.) |
Select class of camshaft bearing same as class of cylinder head as shown on the table below.
Cylinder Head Bore Class | Bearing Class For Installing (Color) | Thickness Of Bearing |
a (A) | C (Green) | 1.996~2.000mm (0.07858~0.07874in.) |
b (B) | B (None color) | 2.000~2.004mm (0.07874~0.07890in.) |
c (C) | A (Black) | 2.004~2.008mm (0.07890~0.07905in.) |
Oil clearance : 0 ~ 0.032mm (0 ~ 0.00126in.)
Inspect the CVVT for smooth rotation.
Clamp the camshaft using a vise. Be careful not to damage the cam lobes and journals in the vise.
Check that the CVVT is locked by turning it clockwise or counterclockwise. It must not rotate.
Intake CVVT : Seal one of the two advance holes in the camshaft journal with tape.
Exhaust CVVT : Seal one of the two retard holes in the camshaft journal with tape.
Intake CVVT : Apply approx. 150 kPa (1.5 kgf/㎠, 21 psi ) of compressed air into the unsealed advance hole to release the lock.
Exhaust CVVT : Apply approx. 150 kPa (1.5 kgf/㎠, 21 psi ) of compressed air into the unsealed retard hole to release the lock.
Cover the oil paths with a piece of cloth when applying compressed air to prevent oil from spraying.
Intake CVVT : With compressed air applied, rotate the CVVT into the advance direction (counterclockwise) within its phasing range and check that the CVVT turns smoothly.
Exhaust CVVT : With compressed air applied, rotate the CVVT into the retard direction (clockwise) and check that the CVVT turns smoothly.
CVVT phasing range
Intake : 22.5˚±1˚ (from the most retarded position to the most advanced position)
Exhaust : 20˚±1˚ (from the most advanced position to the most retarded position)
Intake CVVT : Rotate the CVVT into the most retarded position (clockwise) and then check that the CVVT is locked.
Exhaust CVVT : Rotate the CVVT into the most advanced position (counterclockwise) and then check that the CVVT is locked.
