INFINITI QX4 2001 Factory Service Manual

REMOVALNBEM0042S01Front Engine MountingNBEM0042S0101
SEM458G
ENGINE ASSEMBLY
Removal and Installation (Cont'd)
EM-58

Rear Engine MountingNBEM0042S0102
SEM459G
SEM605G
SEM461G
SEM324F
1. Release fuel pressure.
Refer to EC-39, ªFuel pressure releaseº.
2. Remove engine hood and front RH and LH wheels.
3. Remove engine undercover and suspension member stay.
4. Drain coolant from radiator.
5. Remove the following parts.
IRadiator shroud
IRadiator
ICooling fan
IDrive belts
IBattery
IEngine cover
IThrottle wires
6. Air duct with air cleaner case.
7. Disconnect vacuum hoses, fuel hoses, heater hoses, EVAP
canister hoses, harnesses, connectors and so on.
8. Remove air conditioner compressor from bracket, then put it
aside holding with a suitable wire.
9. Remove power steering oil pump and reservoir tank with
bracket, then put it aside holding with a suitable wire.
10. Remove alternator.
11. Remove exhaust front tube heat insulators, then remove rear
heated oxygen sensors.
12. Remove exhaust front and rear tubes.
Refer to FE-8, ªRemoval and Installationº.
13. Remove transmission with transfer.
Refer to AT-277, ªRemovalº.
14. Remove TWC (manifold) heat insulators, then remove TWC
(manifold).
15. Install engine slingers.
16. Hoist engine with engine slingers and remove front engine
mounting nuts.
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ENGINE ASSEMBLY
Removal and Installation (Cont'd)
EM-59

17. Remove engine from vehicle.
INSTALLATIONNBEM0042S02Installation is in the reverse order of removal.
ENGINE ASSEMBLY
Removal and Installation (Cont'd)
EM-60

ComponentsNBEM0024
SEM584G
1. Rear oil seal retainer
2. Cylinder block
3. Knock sensor
4. Upper main bearing
5. Lower main bearing
6. Oil jet
7. Water drain plug (RH side)
8. Water drain plug (Water pump
side)9. Main bearing cap
10. Main bearing beam
11. Crankshaft
12. Pilot converter
13. Drive plate with signal plate
14. Drive plate reinforce plate
15. Oil ring
16. Piston pin17. Connecting rod bearing
18. Connecting rod
19. Piston
20. Top ring
21. 2nd ring
22. Baffle plate
23. Water drain plug (LH side)
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CYLINDER BLOCK
Components
EM-61

CYLINDER BLOCK HEATERNBEM0024S02
SEM537G
SEM180FA
Removal and InstallationNBEM0025CAUTION:
IWhen installing bearings, pistons, or other sliding parts,
lubricate contacting surfaces with new engine oil.
IPlace removed parts such as bearings and bearing caps
in their proper order and direction.
IWhen installing connecting rod nuts, and main bearing
cap bolts, apply new engine oil to threads and seating
surfaces.
IDo not allow any magnetic materials to contact the signal
plate teeth of drive plate.
SEM190FA
DisassemblyNBEM0026PISTON, CRANKSHAFT AND OIL JETNBEM0026S011. Remove engine. Refer to ªRemoval and Installationº, EM-57.
2. Place engine on a work stand.
3. Drain coolant and oil.
4. Remove oil pan. Refer to ªRemovalº, EM-15.
5. Remove timing chain. Refer to ªRemovalº, EM-23.
6. Remove cylinder head. Refer to ªRemovalº, EM-23.
CYLINDER BLOCK
Components (Cont'd)
EM-62

SEM965A
7. Remove pistons with connecting rods.
IWhen disassembling piston and connecting rod, remove snap
ring first, then heat piston to 60 to 70ÉC (140 to 158ÉF).
8. Remove rear oil seal retainer.
CAUTION:
IWhen piston rings are not replaced, make sure that piston
rings are mounted in their original positions.
IWhen replacing piston rings, if there is no punchmark,
install with either side up.
SEM842E
9. Loosen bolts in numerical order as shown and remove main
bearing beam, bearing cap and crankshaft.
IBefore removing bearing beam and bearing cap, measure
crankshaft end play. Refer to EM-71.
IBolts should be loosened in two or three steps.
SEM454G
10. Remove oil jets.
AEM023
InspectionNBEM0027PISTON AND PISTON PIN CLEARANCENBEM0027S011. Measure inner diameter of piston pin hole ªdpº.
Standard diameter ªdpº:
Grade No. 0
21.993 - 21.999 mm (0.8659 - 0.8661 in)
Grade No. 1
21.999 - 22.005 mm (0.8661 - 0.8663 in)
AEM024
2. Measure outer diameter of piston pin ªDpº.
Standard diameter ªDpº:
Grade No. 0
21.989 - 21.995 mm (0.8657 - 0.8659 in)
Grade No. 1
21.995 - 22.001 mm (0.8659 - 0.8662 in)
3. Calculate interference fit of piston pin to piston.
Dp þ dp = 0.002 - 0.006 mm (0.0001 - 0.0002 in)
If it exceeds the above value, replace piston assembly with pin.
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CYLINDER BLOCK
Disassembly (Cont'd)
EM-63

SEM024AA
PISTON RING SIDE CLEARANCENBEM0027S02Side clearance:
Top ring
0.040 - 0.080 mm (0.0016 - 0.0031 in)
2nd ring
0.030 - 0.070 mm (0.0012 - 0.0028 in)
Oil ring
0.015 - 0.050 mm (0.0006 - 0.0020 in)
Max. limit of side clearance:
Top ring 0.11 mm (0.0043 in)
2nd ring 0.1 mm (0.004 in)
If out of specification, replace piston ring. If clearance exceeds
maximum limit with new ring, replace piston.
SEM599A
PISTON RING END GAPNBEM0027S03End gap:
Top ring 0.23 - 0.33 mm (0.0091 - 0.0130 in)
2nd ring 0.33 - 0.48 mm (0.0130- 0.0189 in)
Oil ring 0.20 - 0.80 mm (0.0079 - 0.0315 in)
Max. limit of ring gap:
Top ring 0.54 mm (0.0213 in)
2nd ring 0.80 mm (0.0315 in)
Oil ring 0.95 mm (0.0374 in)
If out of specification, replace piston ring. If gap still exceeds the
limit even with a new ring, do the following. Rebore cylinder and
use oversized piston and piston rings.
Refer to SDS (EM-82).
IWhen replacing the piston, check the cylinder block surface for
scratches or seizure. If scratches or seizure is found, hone or
replace the cylinder block.
CYLINDER BLOCK
Inspection (Cont'd)
EM-64

SEM038F
SEM003F
CONNECTING ROD BEND AND TORSIONNBEM0027S04Bend:
Limit 0.15 mm (0.0059 in)
per 100 mm (3.94 in) length
Torsion:
Limit 0.30 mm (0.0118 in)
per 100 mm (3.94 in) length
If it exceeds the limit, replace connecting rod assembly.
SEM123C
CYLINDER BLOCK DISTORTION AND WEARNBEM0027S05IClean upper surface of cylinder block.
Use a reliable straightedge and feeler gauge to check the flat-
ness of cylinder block surface.
Check along six positions shown in the figure.
Distortion limit: 0.10 mm (0.0039 in)
IIf out of specification, resurface it. The limit for cylinder block
resurfacing is determined by cylinder head resurfacing in
engine.
Resurfacing limit:
Amount of cylinder head resurfacing is ªAº.
Amount of cylinder block resurfacing is ªBº.
The maximum limit is as follows:
A + B = 0.2 mm (0.008 in)
Nominal cylinder block height from crankshaft center:
214.95 - 215.05 mm (8.4626 - 8.4665 in)
Refer to SDS (EM-81).
IIf necessary, replace cylinder block.
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CYLINDER BLOCK
Inspection (Cont'd)
EM-65

SEM843E
SEM321AA
PISTON-TO-BORE CLEARANCENBEM0027S061. Using a bore gauge, measure cylinder bore for wear, out-of-
round and taper.
Cylinder bore inner diameter
Grade No. Standard inner diameter Wear limit
No. 1 95.500 - 95.510 mm (3.7598 - 3.7602 in)
0.20 mm (0.0079 in) No. 2 95.510 - 95.520 mm (3.7602 - 3.7606 in)
No. 3 95.520 - 95.530 mm (3.7606 - 3.7610 in)
If it exceeds the limit, rebore all cylinders. Replace cylinder
block if necessary.
Out-of-round (X þ Y):
Limit 0.015 mm (0.0006 in)
Taper (AþBþC):
Limit 0.015 mm (0.0006 in)
2. Check for scratches and seizure. If seizure is found, hone it.
SEM451G
IIf both cylinder block and piston are replaced with new
ones, select piston of the same grade number punched on
cylinder block rear position. These numbers are punched
in either Arabic or Roman numerals.
SEM258C
3. Measure piston skirt diameter.
Piston diameter ªAº: Refer to SDS (EM-82).
Measuring point ªaº (Distance from the top):
41.0 mm (1.61 in)
4. Check that piston-to-bore clearance is within specification.
Piston-to-bore clearance ªBº:
0.010 - 0.030 mm (0.0004 - 0.0012 in)
5. Determine piston oversize according to amount of cylinder
wear.
Oversize pistons are available for service.
Refer to SDS (EM-82).
6. Cylinder bore size is determined by adding piston-to-bore
clearance to piston diameter ªAº.
Rebored size calculation: D = A+BþC
where,
D: Bored diameter
A: Piston diameter as measured
B: Piston-to-bore clearance
C: Honing allowance 0.02 mm (0.0008 in)
7. Install main bearing caps, and tighten to the specified torque.
Otherwise, cylinder bores may be distorted in final assembly.
CYLINDER BLOCK
Inspection (Cont'd)
EM-66

8. Cut cylinder bores.
IWhen any cylinder needs boring, all other cylinders must
also be bored.
IDo not cut too much out of cylinder bore at a time. Cut
only 0.05 mm (0.0020 in) or so in diameter at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
10. Measure finished cylinder bore for out-of-round and taper.
IMeasurement should be done after cylinder bore cools
down.
SEM316A
CRANKSHAFTNBEM0027S071. Check crankshaft main and pin journals for score, wear or
cracks.
2. With a micrometer, measure journals for taper and out-of-
round.
Out-of-round (X þ Y):
Standard
0.002 mm (0.0001 in)
Taper (A þ B):
Standard
0.002 mm (0.0001 in)
SEM346D
3. Measure crankshaft runout.
Runout (Total indicator reading):
Limit 0.10 mm (0.0039 in)
SEM175F
BEARING CLEARANCENBEM0027S08IUse either of the following two methods, however, method ªAº
gives more reliable results and is preferable.
Method A (Using bore gauge & micrometer)
Main bearingNBEM0027S08011. Set main bearings in their proper positions on cylinder block
and main bearing cap.
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CYLINDER BLOCK
Inspection (Cont'd)
EM-67