IDX INFINITI QX4 2001 Factory Service Manual

SEM012A
3. Measure outer diameter of camshaft journal.
Standard outer diameter:
No. 1: 25.935 - 25.955 mm (1.0211 - 1.0218 in)
No. 2, 3, 4: 23.445 - 23.465 mm (0.9230 - 0.9238 in)
4. If clearance exceeds the limit, replace camshaft and/or cylin-
der head.
Camshaft journal clearance:
Standard
No. 1: 0.045 - 0.086 mm (0.0018 - 0.0034 in)
No. 2, 3, 4: 0.035 - 0.076 mm (0.0014 - 0.0030 in)
Limit
0.15 mm (0.0059 in)
SEM864E
CAMSHAFT END PLAYNBEM0019S061. Install camshaft in cylinder head.
2. Measure camshaft end play.
Camshaft end play:
Standard
0.115 - 0.188 mm (0.0045 - 0.0074 in)
Limit
0.24 mm (0.0094 in)
SEM865E
CAMSHAFT SPROCKET RUNOUTNBEM0019S071. Install sprocket on camshaft.
2. Measure camshaft sprocket runout.
Runout (Total indicator reading):
Less than 0.15 mm (0.0059 in)
3. If it exceeds the limit, replace camshaft sprocket.
SEM178F
VALVE GUIDE CLEARANCENBEM0019S081. Measure valve deflection as shown in the figure. (Valve and
valve guide mostly wear in this direction.)
Valve deflection limit (Dial gauge reading):
Intake 0.24 mm (0.0094 in)
Exhaust 0.28 mm (0.0110 in)
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CYLINDER HEAD
Inspection (Cont'd)
EM-43

SEM934C
VALVE SEATSNBEM0019S10Check valve seats for any evidence of pitting at valve contact
surface, and reseat or replace if it has worn out excessively.
IBefore repairing valve seats, check valve and valve guide
for wear. If they have worn, replace them. Then correct
valve seat.
IUse both hands to cut uniformly.
SEM795A
REPLACING VALVE SEAT FOR SERVICE PARTSNBEM0019S111. Bore out old seat until it collapses. Boring should not continue
beyond the bottom face of the seat recess in cylinder head. Set
the machine depth stop to ensure this.
2. Ream cylinder head recess for service valve seat.
Oversize [0.5 mm (0.020 in)]:
Intake 38.500 - 38.516 mm (1.5157 - 1.5164 in)
Exhaust 32.700 - 32.716 mm (1.2874 - 1.2880 in)
Be sure to ream in circles concentric to the valve guide
center.
This will enable valve seat to fit correctly.
SEM892B
3. Heat cylinder head to 110 to 130ÉC (230 to 266ÉF) by soaking
in heated oil.
4. Press fit valve seat until it seats on the bottom.
5. Cut or grind valve seat using suitable tool to the specified
dimensions as shown in SDS (EM-79).
6. After cutting, lap valve seat with abrasive compound.
7. Check valve seating condition.
Seat face angle ªaº: 45É
Contacting width ªWº:
Intake 1.09 - 1.31 mm (0.0429 - 0.0516 in)
Exhaust 1.29 - 1.51 mm (0.0508 - 0.0594 in)
SEM621F
8. Use a depth gauge to measure the distance between the
mounting surface of the cylinder head spring seat and the
valve stem end. If the distance is shorter than specified, repeat
step 5 above to adjust it. If it is longer, replace the valve seat
with a new one.
Valve seat resurface limit ªLº:
Intake 41.07 - 41.67 mm (1.6169 - 1.6405 in)
Exhaust 41.00 - 41.60 mm (1.6142 - 1.6378 in)
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CYLINDER HEAD
Inspection (Cont'd)
EM-45

SEM867E
Lifter guide bore diameter:
35.000 - 35.021 mm (1.3780 - 1.3788 in)
SEM085D
AssemblyNBEM00201. Install valve component parts.
IAlways use new valve oil seal. Refer to ªVALVE OIL
SEALº, EM-35.
IBefore installing valve oil seal, install valve spring seat.
IInstall valve spring (uneven pitch type) with its narrow
pitch side toward cylinder head side (paint mark).
IAfter installing valve component parts, tap valve stem tip with
plastic hammer to assure a proper fit.
SEM891E
InstallationNBEM00211. Before installing rear timing chain case, remove old liquid gas-
ket from mating surface using a scraper.
IAlso remove old liquid gasket from mating surface of cylinder
block.
SEM161F
IRemove old liquid gasket from the bolt hole and thread.
SEM892E
2. Before installing cam bracket, remove old liquid gasket from
mating surface using a scraper.
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CYLINDER HEAD
Inspection (Cont'd)
EM-47

SEM877EA
SEM878EA
SEM879EA
5. Install cylinder head outside bolts.
ITightening procedure:
a.Tighten all bolts to 98 N´m (10 kg-m, 72 ft-lb).
b.Completely loosen all bolts.
c.Tighten all bolts to 34 to 44 N´m (3.5 to 4.5 kg-m, 25 to 33
ft-lb).
d.Turn all bolts 90 to 95 degrees clockwise.
e.Turn all bolts 90 to 95 degrees clockwise.
ITighten in numerical order shown in the figure.
SEM444G
6. Install camshaft chain tensioners on both sides of cylinder
head.
SEM652F
7. Install exhaust and intake camshafts and camshaft brackets.
IIntake camshaft has a drill mark on camshaft sprocket
mounting flange. Install it on the intake side.
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CYLINDER HEAD
Installation (Cont'd)
EM-49

SEM885EA
SEM886EA
ITighten the camshaft brackets in the following steps.
Step Tightening torque Tightening order
1 1.96 N´m (0.2 kg-m, 17 in-lb)Tighten in the order of 7 to 10,
then tighten 1 to 6.
2 5.88 N´m (0.6 kg-m, 52 in-lb) Tighten in the numerical order.
39.02 - 11.8 N´m (0.92 - 1.20 kg-m,
79.9 - 104.2 in-lb)Tighten in the numerical order.
SEM443G
9. Install CVTC valves.
SEM534G
10. Install O-rings to cylinder block.
SEM447G
11. Install O-rings to cylinder head.
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CYLINDER HEAD
Installation (Cont'd)
EM-51

SEM418G
ICheck that valve lifters on No. 1 cylinder are loose and valve
lifters on No. 4 are tight.
If not, turn crankshaft one revolution (360É) and align as above.
SEM893E
7. Check only those valves shown in the figure.
Crank
positionValve
No. 1 No. 2 No. 3 No. 4 No. 5 No. 6
INT EXH INT EXH INT EXH INT EXH INT EXH INT EXH
No. 1 TDCqqq q
SEM139D
IUsing a feeler gauge, measure clearance between valve lifter
and camshaft.
IRecord any valve clearance measurements which are out of
specification. They will be used later to determine the required
replacement adjusting shim.
Valve clearance for checking (Cold):
Intake
0.26 - 0.34 mm (0.010 - 0.013 in)
Exhaust
0.29 - 0.37 mm (0.011 - 0.015 in)
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CYLINDER HEAD
Valve Clearance (Cont'd)
EM-53

SEM869EA
4. Place Tool (A) around camshaft as shown in figure.
Before placing Tool (A), rotate notch toward center of cyl-
inder head (See figure.), to simplify shim removal later.
CAUTION:
Be careful not to damage cam surface with Tool (A).
5. Rotate Tool (A) (See figure.) so that valve lifter is pushed down.
SEM870E
6. Place Tool (B) between camshaft and the edge of the valve
lifter to retain valve lifter.
CAUTION:
ITool (B) must be placed as close to camshaft bracket as
possible.
IBe careful not to damage cam surface with Tool (B).
7. Remove Tool (A).
SEM871E
8. Blow air into the hole to separate adjusting shim from valve
lifter.
SEM872E
SEM145D
9. Remove adjusting shim using a small screwdriver and a mag-
netic finger.
10. Determine replacement adjusting shim size following formula.
IUsing a micrometer determine thickness of removed shim.
ICalculate thickness of new adjusting shim so valve clearance
comes within specified values.
R = Thickness of removed shim
N = Thickness of new shim
M = Measured valve clearance
Intake:
N=R+[Mþ0.30 mm (0.0118 in)]
Exhaust:
N=R+[Mþ0.33 mm (0.0130 in)]
Shims are available in 64 sizes from 2.32 mm (0.0913 in)
to 2.95 mm (0.1161 in), in steps of 0.01 mm (0.0004 in).
ISelect new shim with thickness as close as possible to calcu-
lated value.
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CYLINDER HEAD
Valve Clearance (Cont'd)
EM-55

Removal and InstallationNBEM0042WARNING:
ISituate vehicle on a flat and solid surface.
IPlace chocks at front and back of rear wheels.
IDo not remove engine until exhaust system has com-
pletely cooled off. Otherwise, you may burn yourself
and/or fire may break out in fuel line.
IFor safety during subsequent steps, the tension of wires
should be slackened against the engine.
IBefore disconnecting fuel hose, release fuel pressure
from fuel line.
Refer to EC-39, ªFuel Pressure Releaseº.
IBefore removing front axle from transmission, place
safety stands under designated front supporting points.
Refer to GI section for lifting points and towing.
IBe sure to hoist engine and transmission in a safe man-
ner.
IFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATALOG.
CAUTION:
IWhen lifting engine, be careful not to strike adjacent parts,
especially accelerator wire casing, brake lines, and brake
master cylinder.
IIn hoisting the engine, always use engine slingers in a
safe manner.
IBefore separating engine and transmission, remove
crankshaft position sensor (POS) from the assembly.
IAlways take extra care not to damage edge of crankshaft
position sensor (POS), or ring gear teeth.GI
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ENGINE ASSEMBLY
Removal and Installation
EM-57

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

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