Engine Mechanical – V6 Page 6A1–172
Valve Margin Measurement Procedure
1 Measure the valve margin using an appropriate scale.
2 Refer to 5 Specifications for minimum valve margin and compare them to your measurements.
3 If the valve margins are beyond specification, replace the valves.
4 If the valve margins are within specification and do not require refacing, test the valve for seat
concentricity, refer to Valve-to-Seat Concentricity
Measurement Procedure in this Section.
Figure 6A1 – 294
Valve-to-Seat Concentricity Measurement Procedure
Checking the valve-to-seat concentricity determines whether the valve and seat are sealing correctly.
Measure the valve face and the valve seat to ensure correct valve sealing.
1 Coat the valve face lightly with blue dye (3).
2 Install the valve in the cylinder head.
3 Turn the valve against the seat with enough pressure to wear off the dye.
4 Remove the valve from the cylinder head.
5 Inspect the valve face.
NOTE
• If the valve face is concentric, providing a
correct seal, with the valve stem, a continuous
mark (1) will be made around the entire face (2).
• The wear mark must be at least 0.5 mm from
the margin of the valve. If the wear mark is too
close to the margin, the seat must be
reconditioned to move the contact area away
from the margin.
• If the face is not concentric with the stem, the
mark will not be continuous around the valve
face. The valve should be refaced or replaced
and the seat must be reconditioned, refer to
Valve and Seat Reconditioning Procedure in
this Section.
Figure 6A1 – 295
Valve and Seat Reconditioning Procedure
If the valve seat width, roundness or concentricity are beyond specifications, grind the seats in order to ensure correct
heat dissipation and prevent the build up of carbon on the seats.
If valve seat reconditioning is required, reface the valve face, unless a new valve is used.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–184
4 Major Service Operations
ATTENTION
The V6 engine is a combination of numerous components, containing machined, honed, polished and lapped
surfaces manufactured on the latest, high technology production equipment. Many of the components
contain tolerances measured in thousandths of a millimetre. Consequently, when any engine component is to
be serviced, care and cleanliness are extremely important.
Prior to re-assembly of the V6 engine, all components must be cleaned and inspected in accordance with the
relevant procedures throughout this section, and replaced or repaired where required.
In addition to cleaning and inspecting components, a liberal coating of engine oil should be applied to friction
surfaces during assembly to protect and lubricate the surfaces on initial operation.
When performing any service operation contained in this Section, it should be understood that correct
cleaning and protection of machined surfaces and friction areas is part of the repair procedure. This is
considered standard workshop practice, even if not specifically stated. Torque values must be used as
specified during reassembly to ensure correct retention of all components.
Through out this section, fastener torque wrench specifications may be accompanied with the following
identification marks:
■ Fasteners must be replaced after loosening.
Fasteners either have micro encapsulated sealant applied or incorporate a mechanical thread lock and
should only be re-used once. If in doubt, replacement is recommended.
If one of these identification marks is present alongside a fastener torque wrench specification, the
recommendation regarding that fastener must be adhered to.
4.1 Engine Removal
CAUTION
• Allow the engine to cool to at least 50 °
°°
°
C,
before attempting fastener removal.
• As aluminium has a greater rate of thermal
expansion than that of cast iron,
aluminium bolt hole threads will change
dimension to a larger extent than cast iron
bolt threads.
• If a bolt or other threaded component is
removed before the engine is allowed to
cool to at least 50 °
°°
°
C, threads could be
pulled from the cylinder block or cylinder
head.
• Do not use impact tools to remove bolts
during engine disassembly. While this may
be common practice with cast iron engine
components, use of these tools is likely to
pull the aluminium threads in the cylinder
block or head of this engine.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–198
k Timing chains, tensioners, shoes, guides & sprockets, refer to 3.16 Timing Chains, Tensioners, Shoes and
Guides.
l Cylinder head assemblies, refer to 3.22 Cylinder Head Assembly.
m Oil pan assembly, refer to 4.2 Oil Pan and Oil Pump Suction Pipe Assembly.
n Piston and connecting rod assemblies, refer to 4.5 Pistons, Pins, Rings, Connecting Rods and Big-end Bearings.
o Crankshaft assembly, refer to 4.6 Crankshaft and Main Bearings.
p Piston oil nozzles, refer 4.5 Pistons, Pins, Rings, Connecting Rods and Big-end Bearings.
Reassemble
Reassembly of the engine assembly is the reverse of the disassembly procedure.
Reinstall
Reinstallation of the engine assembly is the reverse to the removal procedure, noting the following:
NOTE
Refer to 6 Torque Wrench Specifications
for the correct torque specifications.
1 Tighten the fasteners to the correct torque specification.
Engine ground connector bolt
torque specification ............................................10.0 Nm
Power steering high pressure line
attaching bolt torque specification .............8.0 – 12.0 Nm
Power steering high pressure line
flare nut torque specification ...................25.0 – 35.0 Nm
Engine mount to frame attaching bolt
torque specification .................................44.0 – 60.0 Nm
Knock Sensor Attaching Nut
torque specification ............................................23.0 Nm
2 Use only the specified engine lubricant type and quantity. It is recommended that a fluorescent oil dye, such as that contained in J 28481-B, be added to assist in any future oil leak diagnosis.
3 Fill the cooling system with the correct quantity and grade of coolant, refer to 6B1 Engine Cooling – V6.
4 Check transmission fluid level, replenishing as required, using the specified lubricant for the transmission fitted, refer to 7C1 Automatic – 4L60E – General Information.
5 Disable the ignition system, refer to 6C1-3 Engine Management – V6 – Service Operations.
6 Crank the engine several times. Listen for any unusual noises or evidence that parts are binding.
7 Enable the ignition system. Start the engine and listen for any unusual noises.
8 Check the vehicle oil pressure gauge or warning indicator and confirm the engine has acceptable oil pressure. If required, install an oil pressure gauge and measure the engine oil pressure, refer to 2.19 Engine Oil Pressure
Diagnosis.
9 Run the engine at about 1,000 r.p.m. until the engine has reached normal operating temperature.
10 Listen for any unusual noises.
11 Check for oil, fuel, coolant and exhaust leaks while the engine is running, correcting as required.
12 Perform a final inspection for correct engine oil and coolant levels.
4.2 Oil Pan and Oil Pump Suction Pipe Assembly
Remove
1 Remove the engine assembly from the vehicle, refer to 4.1 Engine .
2 Separate the engine and transmission assemblies, refer to 7C1 Automatic – 4L60E – General Information.
3 Mount the engine assembly on a suitable engine stand.
4 Remove the engine front cover, refer to 3.15 Front Cover Assembly.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–216
Connecting Rod Measurement Procedure
Piston Pin End
NOTE
Measurements of all components should be
taken with the components at normal room
temperature.
1 Using an outside micrometer (1), take two measurements of the piston pin (2) in the area of the
connecting rod contact.
Figure 6A1 – 392
2 Using an inside micrometer, measure the connecting rod piston pin bore (1).
3 Subtract the piston pin diameter from the piston pin bore.
4 Compare the clearance measurements listed in the specifications, refer to 5 Specifications.
5 If the clearance is excessive, replace the piston pin. If a new pin does not resolve the clearance problem,
replace the connecting rod.
Figure 6A1 – 393
Crankshaft Bearing End
NOTE
Measurements of all components should be
taken with the components at normal room
temperature.
1 Using an inside micrometer, measure the connecting rod crankshaft bearing bore (1).
2 Compare the bore measurements listed in the specifications, refer to 5 Specifications.
3 Replace the connecting rod if the bore is out of specification. Do not recondition the connecting rod.
Figure 6A1 – 394
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–218
Piston Ring
NOTE
The ends of the expander must be facing
toward the top of the piston.
1 Correctly orient the oil control ring expander (1) before installation.
Figure 6A1 – 397
2 Using a piston ring expander, install the oil control ring assembly using the following procedure:
3 Install the expander ring (3).
4 Install the two oil scraper rings (4). Expand the rings only enough to clear the piston diameter. Over-
expanding the piston rings will distort or crack the
rings.
5 Install the second (2) and top (1) piston rings as follows.
Figure 6A1 – 398
6 Using the ring expander (1), install the second piston ring (2) onto the piston (3). Do not over-expand the
ring. Repeat for the top ring.
Figure 6A1 – 399
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–219
7 Once the rings are installed, set the ring gaps for the
oil control, second and top ring as follows. Use the
piston location arrow for reference.
• Lower oil control ring position (1).
• Upper oil control ring position (2).
• Top ring position (3).
• Oil control ring expander position (4).
• Second ring position (5).
Figure 6A1 – 400
Connecting Rod Bearing
CAUTION
If the connecting rod bearings have been
used in a running engine, they must be
replaced with new connecting rod bearings
for reassembly.
1 Clean the connecting rod (2) and the connecting rod cap bearing bore with a lint-free cloth.
2 Clean the oil from behind the connecting rod bearing halves.
3 Install a new upper connecting rod bearing (1) into position. Roll the bearing into position so the lock tang
engages the alignment slot. The bearing must fit flush
in the connecting rod.
Figure 6A1 – 401
4 Install the lower connecting rod bearing (1) into position in the connecting rod cap (2).
5 Roll the bearing into position so the lock tang engages the alignment slot. The bearing must fit flush
with the connecting rod cap.
Figure 6A1 – 402
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–239
Inspect
Visual Inspection
NOTE
The following procedure assumes the engine has
been disassembled and cleaned, as described
above.
1 Inspect the crankshaft bearing journals for damage or spun bearings. The crankshaft bearing journals are not repairable and if damage is found, the cylinder block assembly must be replaced.
2 Inspect the primary camshaft chain tensioner mounting surface on the engine block for burrs or any defects that would affect the sealing of the new primary camshaft chain tensioner gasket.
3 Inspect all sealing and mating surfaces for damage, repair or replace the cylinder block assembly if required.
4 Inspect all threaded and through holes for damage or excessive debris.
5 Inspect all bolts for damage, if damaged replace with new bolts only.
6 Inspect the cylinder walls for cracks or damage. The cylinder sleeves are not serviced separately, if the cylinders are damaged the cylinder block assembly must be replaced.
7 Inspect the engine block for cracks. Do not repair any cracks. If cracks are found, the cylinder block assembly must be replaced. Repair any damaged threaded holes, refer to 4.9 Thread Repair Specifications.
Measuring Cylinder Bore Diameter
1 Measure the cylinder bore diameter 37 mm from the deck face (1) using a commercially available bore
gauge or Tool No. J-8087 (2).
2 Record the results and compare with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of
oversized pistons and rings are available for
service. If the cylinder bore diameter exceeds
specification by more than 0.25 mm, the
cylinder block must be replaced.
Figure 6A1 – 448
Measuring Cylinder Bore Taper
1 Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centreline, at 10 mm below the deck surface and record the measurement.
2 Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centreline, at 100 mm below the deck surface and record the measurement.
3 Calculate the difference between the two measurements. The result will be the cylinder taper.
4 Compare the results with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of oversized
pistons and rings are available for service. If the
cylinder bore diameter exceeds specification by
more than 0.25 mm, the cylinder block must be
replaced.
Measuring Cylinder Bore Out-of-Round
1 Measure both the thrust and non-thrust cylinder diameter at 10 mm below the deck. Record your measurements.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–240
2 Calculate the difference between the two measurements. The result will indicate out-of-round at the upper end of
the cylinder.
3 Measure both the thrust and non-thrust cylinder diameter at 100 mm below the deck surface. Record your measurements.
4 Calculate the difference between the two measurements. The result will indicate out-of-round at the lower end of the cylinder.
5 Compare your results with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of oversized
pistons and rings are available for service. If the
cylinder bore diameter exceeds specification by
more than 0.25 mm, the cylinder block must be
replaced.
Deck Flatness Inspection
1 Ensure the engine block decks are clean and free of gasket material.
2 Inspect the surface for any imperfections or scratches that could inhibit correct cylinder head gasket sealing.
3 Place a straight-edge diagonally across the cylinder block deck face surface.
4 Measure the clearance between the straight-edge and the cylinder block deck face using a feeler gauge
at 4 points along the straight-edge.
5 If the warpage is less than 0.05 mm, the cylinder block deck surface does not require resurfacing.
6 If the warpage is between 0.05 ±0.20 mm or any imperfections or scratches that could inhibit correct
cylinder head gasket sealing are present, the cylinder
block deck surface requires resurfacing.
7 If resurfacing is required the maximum amount that can be removed is 0.25 mm.
8 If the cylinder block deck surface requires more than 0.25 mm material removal the block must be
replaced.
Figure 6A1 – 449
Reassemble
1 Install the cylinder block-to-cylinder head alignment
dowels (1).
Figure 6A1 – 450
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ISUZU KB P190 2007