ISUZU KB P190 2007 Workshop Repair Manual

6A – 56 ENGINE MECHANICAL



MINOR COMPONENTS
ROCKER ARM SHAFT AND ROCKER ARM




Disassembly Steps
1. Rocker arm shaft snap ring 5. Rocker arm shaft spring
2. Rocker arm 6. Rocker arm shaft snap ring
3. Rocker arm shaft bracket 7. Rocker arm shaft
4. Rocker arm


Disassembly


1. Rocker Arm Shaft Snap Ring
2. Rocker Arm
3. Rocker Arm Shaft Bracket
1. Use a pair of pliers to remove the snap rings.
2. Remove the rocker arms.
3. Remove the rocker arm shaft brackets. If the rocker arms and rocker arm shaft brackets are to
be reinstalled, mark their installation positions by
tagging each rocker arm and rocker arm shaft bracket
with the cylinder number from which it was removed.
4. Rocker Arm
5. Rocker Arm Shaft Spring
6. Rocker Arm Shaft Snap Ring
7. Rocker Arm Shaft

011RY00009
011RY00010

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE MECHANICAL 6A – 57
CYLINDER HEAD


RTW46ALF001201


Disassembly Steps
1.
Intake manifold 6.
Intake and exhaust valve
2.
Intake manifold gasket 7.
Valve stem oil seal
3.
Split collar 8.
Valve spring lower seat
4.
Valve spring upper seat 9.
Cylinder head
5.
Valve spring

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6A – 58 ENGINE MECHANICAL






















Disassembly
1. Intake Manifold
2. Intake Manifold Gasket
3. Split Collar
1. Place the cylinder head on a flat wooden surface.
2. Use the spring compressor to remove the split collars. Do not allow the valve to fall from the cylinder head.
Spring Compressor: 9-8523-1423-0
4. Valve Spring Upper Seat
5. Valve Spring



6. Intake and Exhaust Valve
If the intake and exhaust valves are to be reinstalled, mark
their installation positions by tagging each valve with the
cylinder number from which it was removed.
If the intake and exhaust valves are to be replaced, the
valve guides must also be replaced.
7. Valve Stem Oil Seal
8. Valve Spring Lower Seat
9. Cylinder Head


011RY00011
011LX022

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE MECHANICAL 6A – 59

PISTON AND CONNECTING ROD


RTW46ALF000301


Disassembly Steps
1.
Connecting rod bearing 4.
Piston pin
2.
Piston ring 5.
Connecting rod
3.
Piston pin snap ring 6.
Piston

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6A – 60 ENGINE MECHANICAL



RTW36ASH001501
Disassembly
1. Connecting Rod Bearing
If the connecting rod bearings are to be reinstalled, mark
their fitting positions by tagging each bearing with the
cylinder number from which it was removed.






015RW041
2. Piston Ring
1. Clamp the connecting rod in a vise. Take care not to damage the connecting rod.
2. Use a piston ring replacer to remove the piston rings. Piston Ring Replacer
Do not attempt to use some other tool to remove the
piston rings. Piston ring stretching will result in
reduced piston ring tension.





3. Piston Pin Snap Ring Use a pair of pliers to remove the piston pin snap rings.





RTW36ASH001601
4. Piston Pin
5. Connecting Rod
6. Piston
Tap the piston pin out with a hammer and a brass bar.
If the pistons and piston pins are to be reinstalled, mark
their installation positions by tagging each piston and piston
pin with the cylinder number from which it was removed.
F06MV015

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE MECHANICAL 6A – 61

INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during
inspection.





CYLINDER HEAD
Cylinder Head Lower Face Warpage
1. Use a straight edge and a feeler gauge to measure the four sides and the two diagonals of the cylinder head lower
face.
2. The cylinder head lower surface warpage is more than the limit, it should be replaced.


Cylinder Head Lower Face Warpage mm (in)
Standard Limit
0.05
(0.002) or less 0.20
(0.0079)




NOTE:
The cylinder head lower face cannot be reground.

Cylinder Head Height (
H) (Reference) mm (in)
Standard
91.95 – 92.05
(3.620 – 3.624)






Positive Crankcase Ventilation (PCV) Valve
1. Remove PCV valve assembly from cylinder head cover.
2. Inspect the diaphragm for broken.
3. Inspect the spring for broken or weaken.
4. If find any abnormal condition, replace the PCV valve assembly.

011RY00012
011RY00013011RY00014

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6A – 62 ENGINE MECHANICAL





















Manifold Fitting Face Warpage
Use a straight edge and a feeler gauge to measure the
manifold cylinder head fitting face warpage.
Regrind the manifold cylinder head fitting surfaces if the
measured values are greater than the specified limit but less
than the maximum grinding allowance.
If the measured values exceed the maximum grinding
allowance, the cylinder head must be replaced.


Manifold Fitting Face Warpage mm (in)
Standard Limit Maximum Grinding
Allowance
0.05
(0.002) or less 0.20
(0.008) 0.40
(0.016)



















Exhaust Manifold Warpage
Use a straight edge and a feeler gauge to measure the
manifold cylinder head fitting face warpage.
If the measured values exceed the specified limit, the manifold
must be replaced.


Exhaust Manifold Warpage mm (in)
Standard Limit
0.05 (0.002) or less 0.20 (0.008)



























Valve Stem and Valve Guide Clearance
Measuring Method-I
1. With the valve stem inserted in the valve guide, set the dial indicator needle to "0".
2. Move the valve head from side to side. Read the dial indicator.
Note the highest dial indication.
If the measured values exceed the specified limit, the valve
and the valve guide must be replaced as a set.


Valve Stem Clearance mm (in)
Standard Limit
Intake Valve 0.039 - 0.071
(0.0015 - 0.0028) 0.200
(0.008)
Exhaust Valve 0.064 - 0.096
(0.0025 - 0.0038) 0.250
(0.0098)
027RY00001
027RY00002
011RY00022

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE MECHANICAL 6A – 63


Measuring Method-II
1. Measure the valve stem outside diameter. Refer to the Item "Valve Stem Outside Diameter".
2. Use a caliper calibrator or a telescoping gauge to measure the valve guide inside diameter.













Valve Guide Replacement
Valve Guide Removal
Use a hammer and the valve guide replacer to drive out the
valve guide from the cylinder head lower face.
Valve Guide Replacer: 9-8523-1212-0













Valve Guide Installation
1. Apply engine oil to the valve guide outer circumference.
2. Attach the valve guide installer to the valve guide.
3. Use a hammer to drive the valve guide into position from the cylinder head upper face.
Valve Guide Replacer: 9-8523-1212-0











4. Measure the height of the valve guide upper end from the
upper face of the cylinder head.


Valve Guide Upper End Height (H) (Reference) mm (in)
12.8-13.2 (0.50-0.52)
NOTE:
If the valve guide has been removed, both the valve
and the valve guide must be replaced as a set.

011LX029
011RY00024
011RY000025 011RY00023

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

6A – 64 ENGINE MECHANICAL














Valve Stem Outside Diameter
Measure the valve stem diameter at three points.
If the measured value is less than the specified limit, the valve
and the valve guide must be replaced as a set.


Valve Stem Outside Diameter mm (in)
Standard Limit
Intake Valve 7.946 - 7.961
(0.3128 - 0.3134) 7.880
(0.3102)
Exhaust Valve 7.921 - 7.936
(0.3119 - 0.3124) 7.850
(0.3090)

















Valve Thickness
Measure the valve thickness.
If the measured value is less than the specified limit, the valve
and the valve guide must be replaced as a set.


Intake and Exhaust Valve Thickness mm (in)
Standard Limit
4JA1T (L) 1.8 (0.07) 1.5 (0.06)
Inlet 1.34 (0.054) 4JA1TC,
4JH1TC Exhaust 1.36 (0.055) 1.1 (0.045)




















Valve Depression
1. Install the valve (1) to the cylinder head (2).
2. Use a depth gauge or a straight edge with steel rule to measure the valve depression from the cylinder head lowe
r
surface.
If the measured value exceeds the specified limit, the valve
seat insert must be replaced.


Valve Depression mm (in)
Standard Limit
4JA1T(L) 0.72 (0.029) 1.28 (0.050)
4JA1TC, 4JH1TC 1.17 (0.048) 1.67 (0.068)

011LX027
014RY00020 014RY00021

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

ENGINE MECHANICAL 6A – 65
















Valve Contact Width
1. Check the valve contact faces for roughness and unevenness. Make smooth the valve contact surfaces.
2. Measure the valve contact width. If the measured value exceeds the specified limit, the valve
seat insert must be replaced.

Valve Contact Width mm (in)
Standard Limit
Intake 1.7 (0.067) 2.2 (0.087)
Exhaust 2.0 (0.079) 2.5 (0.078)
























Valve Seat Insert Replacement
Valve Seat Insert Removal
1. Arc weld the entire inside circumference (1) of the valve seat insert (2).
2. Allow the valve seat insert to cool for a few minutes. This will invite contraction and make removal of the valve
seat insert easier.
3. Use a screwdriver (3) to pry the valve seat insert free. Take care not to damage the cylinder head (4).
4. Carefully remove carbon and other foreign material from the cylinder head insert bore.


014RY00027
011LX039

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007