Kia Optima: 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 surfaceStandard : 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.)
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| 2. |
Inspect for cracks. Check the
combustion chamber, intake ports, exhaust ports and cylinder block surface
for cracks. If cracked, replace the cylinder head.
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Valve And Valve Spring
| 1. |
Inspect valve stems and valve
guides.
| (1) |
Using a caliper gauge,
measure the inside diameter of the valve guide.
Valve guide inner
diameterIntake / Exhaust : 5.500 ~ 5.512mm (0.21654 ~
0.21701in.)
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|
| (2) |
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.)
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|
| (3) |
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. |
|
| 2. |
Inspect the valves.
| (1) |
Check the valve is ground
to the correct valve face angle. |
| (2) |
Check that the surface
of the valve for wear. If the valve face is worn, replace the
valve.
|
| (3) |
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. |
| (4) |
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.)
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| (5) |
Check the surface of
the valve stem tip for wear. If the valve stem tip is worn, replace
the valve.
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| 3. |
Inspect the valve seats
| (1) |
Check the valve seat
for evidence of overheating and improper contact with the valve
face. Replace the cylinder head if necessary. |
| (2) |
Check the valve guide
for wear. If the valve guide is worn, replace the cylinder head. |
|
| 4. |
Inspect the valve springs.
| (1) |
Using a steel square,
measure the out-of-square of the valve spring. |
| (2) |
Using a vernier calipers,
measure the free length of the valve spring.
Valve spring[Standard]
Free height : 47.44mm (1.8677in.)Out-of-square : Less
than 1.5°
|
If the free length is not as specified, replace the valve spring. |
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MLA (Mechanical Lash Adjuster)
| 1. |
Inspect the MLA. Using a micrometer,
measure the MLA outside diameter.
MLA outer diameter :31.964
~ 31.980mm (1.2584 ~ 1.2590in.)
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|
| 2. |
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.)
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|
| 3. |
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.)
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|
Camshaft
| 1. |
Inspect the cam lobes. Using
a micrometer, measure the cam lobe height.
Cam height[Standard value]
Intake : 44.10 ~ 44.30mm (1.7362 ~ 1.7440in.)Exhaust : 44.90
~ 45.10mm (1.7677 ~ 1.7756in.)
|
If the cam lobe height is less than standard, 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.
|
Do not turn the camshaft. |
|
| (5) |
Remove the bearing caps. |
| (6) |
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. |
| (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 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. |
| (3) |
Remove the camshafts. |
|
Exhaust Camshaft Bearing
| 1. |
Check the cylinder head bore
mark. Cylinder Head Bore Identification Mark
Cylinder Head Specifications
Class
|
Mark
|
Exhaust No.1 Inside Diameter Of Cylinder Head Bore
|
a
|
A
|
40.000 ~ 40.008mm
(1.57480 ~ 1.5751in.)
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b
|
B
|
40.008 ~ 40.016mm
(1.57511 ~ 1.57543in.)
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c
|
C
|
40.016 ~ 40.021mm
(1.57543 ~ 1.57563in.)
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| 2. |
Select class of camshaft bearing
same as class of cylinder head as shown on the table below. Exhaust Camshaft
Bearing Identification Mark
Exhaust Camshaft Bearing Specifications
Cylinder
Head Bore
Class
|
Bearing Class For Installing (Color)
|
Thickness Of Bearing
|
a (A)
|
C (Green)
|
1.996~2.000mm
(0.07858~0.07874in.)
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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.)
|
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CVVT Assembly
| 1. |
Inspect CVVT assembly.
| (1) |
Check that the CVVT assembly
will not turn. |
| (2) |
Apply vinyl tape to the
retard hole except the one indicated by the arrow in the illustration.
Verify the hold to tape and the hole to put air in.
[Intake]
![[Exhaust]](images/books/774/sxmm19073l.gif)
[Exhaust]
|
| (3) |
Wind 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.)
|
When the oil splashes, wipe it off with a shop rag and the
likes. |
|
| (4) |
With air applied, as
in step(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. Also, under the condition that
the pressure can be hardly applied because of the air leakage from
the port, there may be the case that the lock pin could be hardly
released.
|
| (5) |
Turn the CVVT assembly
back and forth and check the movable range and that there is no
disturbance.
Standard:Should
move smoothly in a range from about
22.5° (Intake) / 20.0° (Exhaust)
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|
| (6) |
Turn the intake CVVT
assembly with your hand and lock it at the maximum retard angle
position (counter clockwise). |
| (7) |
Turn the exhaust CVVT
assembly with your hand and lock it at the maximum advance angle
position (clockwise). |
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Identify MLA(Mechanical Lash Adjuster), valves, valve springs as they are
removed so that each item can be reinstalled in its origina ...
Thoroughly clean all parts to be assembled.Before installing the parts,
apply fresh engine oil to all sliding and rotating surfaces.
...
Disassembly
Reassembly