Kia Optima: Inspection - Cylinder Head. Repair procedures - Cylinder Head Assembly - Engine Mechanical System - Kia Optima TF 2011-2018 Service ManualKia 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 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.)

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 valve stems and valve guides.
(1) 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.)


(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.)

(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.

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.)
(5) Check the surface of the 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 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.

If the free length is not as specified, replace the valve spring.
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.)


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.)


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.)
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.

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 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

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

Cylinder Head Specifications
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.)

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

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.)
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.)
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]

[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)
(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).

Disassembly
Identify MLA(Mechanical Lash Adjuster), valves, valve springs as they are removed so that each item can be reinstalled in its origina ...

Reassembly
Thoroughly clean all parts to be assembled.Before installing the parts, apply fresh engine oil to all sliding and rotating surfaces. ...

See also:

Inhibitor Switch. Schematic Diagrams
Circuit Diagram ...

Front Fog Light Replacement
1. Turn the bulb socket counter- clockwise and remove the bulb socket. 2. Insert a new bulb in socket. 3. Install the bulb socket. ...

Removal
1. Remove the head lamp leveling unit connector (A). 2. Loosen the mounting bolts (3EA) of automatic head lamp leveling unit assembly. Tighting torq ...

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