2001 INFINITI QX4 engine

SEM426G
7. After confirming the mating marks are aligned, tighten the cam-
shaft sprocket mounting bolts.
ISecure the camshaft hexagonal head using a spanner to
tighten mounting bolts.
SEM425G
8. Pull out the stopper pin from the secondary timing chain ten-
sioner.
SEM919EA
9. Install internal guide.
10. Install upper tension guide and slack guide.
SEM967F
11. Install timing chain tensioner, then remove the stopper pin.
IWhen installing the timing chain tensioner, engine oil
should be applied to the oil hole and tensioner.
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TIMING CHAIN
Installation (Cont'd)
EM-31

SEM439G
SEM440G
17. Install RH and LH rocker covers.
Rocker cover tightening procedure:
ITighten in numerical order as shown in the figure.
a. Tighten bolts 1 to 10 in that order to 6.9 to 8.8 N´m (0.7 to 0.9
kg-m, 61 to 78 in-lb).
b. Then tighten bolts 1 to 10 as indicated in figure to 6.9 to 8.8
N´m (0.7 to 0.9 kg-m, 61 to 78 in-lb).
18. Hang engine using the right and left side engine slingers with
a suitable hoist.
19. Set a suitable transmission jack under the suspension mem-
ber.
20. Remove right and left side engine mounting nuts.
21. Remove right and left side suspension member bolts.
22. Install aluminum oil pan. Refer to EM-18, ªInstallationº.
23. Set ring gear stopper using the mounting bolt hole.
IBe careful not to damage the signal plate teeth.
SEM417G
24. Install crankshaft pulley to crankshaft.
IAlign pointer with TDC mark on crankshaft pulley.
SEM531G
25. Install crankshaft pulley bolt.
ILubricate thread and seat surface of the bolt with new
engine oil.
a. Tighten to 39 to 49 N´m (4.0 to 5.0 kg-m, 29 to 36 ft-lb).
b. Put a paint mark on the crankshaft pulley.
SEM963E
c. Again tighten by turning 60É to 66É, about the angle from one
hexagon bolt head corner to another.
26. Install camshaft position sensor (PHASE), crankshaft position
sensors (REF)/(POS) and CVTC sensors.
27. Reinstall removed parts in the reverse order of removal.
IWhen installing fuel tube and intake manifold collectors, refer
to EM-12, ªTIGHTENING PROCEDURESº.
IAfter starting engine, keep idling for three minutes. Then
rev engine up to 3,000 rpm under no load to purge air from
the high-pressure chamber of the chain tensioners. The
engine may produce a rattling noise. This indicates that
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TIMING CHAIN
Installation (Cont'd)
EM-33

SEM948E
ReplacementNBEM0015CAUTION:
When removing the oil pans, oil pump assembly and timing
chain from engine, first remove the camshaft position sensor
(PHASE), CVTC sensor and the crankshaft position sensors
(REF)/(POS) from the assembly.
Be careful not to damage sensor edges.
VALVE OIL SEALNBEM0015S011. Remove timing chain. Refer to ªRemoval, EM-23.
2. Remove camshaft brackets and camshaft. Refer to
ªDisassemblyº, EM-41.
3. Remove valve lifters and shims.
4. Remove valve spring with Tool.
5. Reinstall any parts removed in reverse order of removal.
Before removing valve spring, fix valve as follows.
Method A:
Piston concerned should be set at TDC to prevent valve
from falling.
SEM826E
Method B:
Remove spark plug, then install air hose adapter into
spark plug hole and apply air pressure to hold valves in
place. Apply a pressure of 490 kPa (5 kg/cm
2, 71 psi).
SEM983D
Method C:
Install spark plug with suitable washer into spark plug
hole from combustion chamber side.
SEM827E
6. Remove valve oil seal.
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OIL SEAL
Replacement
EM-35

SEM828E
7. Apply engine oil to new valve oil seal and install it with Tool.
SEM715A
OIL SEAL INSTALLATION DIRECTIONNBEM0015S02IInstall new oil seal in the direction shown in the figure.
FRONT OIL SEALNBEM0015S031. Remove the following parts:
IEngine undercover
ISuspension member stay
IDrive belts
ICrankshaft position sensor (REF)
Be careful not to damage sensor edge.
ICrankshaft pulley
IRadiator
ICooling fan
SEM829E
2. Remove front oil seal using a suitable tool.
Be careful not to scratch front cover.
3. Apply engine oil to new oil seal and install it using a suitable
tool.
SEM830E
REAR OIL SEALNBEM0015S041. Remove transmission. Refer to AT-277, ªRemovalº.
2. Remove drive plate.
3. Remove oil pan. Refer to EM-15.
4. Remove rear oil seal retainer.
OIL SEAL
Replacement (Cont'd)
EM-36

CAUTION:
IWhen installing camshafts, chain tensioners, oil seals, or
other sliding parts, lubricate contacting surfaces with new
engine oil.
IApply new engine oil to threads and seat surfaces when
installing cylinder head, camshaft sprocket, crankshaft
pulley, and camshaft bracket.
IAttach tags to valve lifters so as not to mix them up.
RemovalNBEM00171. Remove engine from vehicle. Refer to EM-57, ªRemoval and
Installationº.
2. Remove exhaust manifolds in reverse order of installation.
Refer to EM-13, ªExhaust Manifoldº.
3. Place engine on a work stand.
4. Remove aluminum oil pan. Refer to EM-15, ªRemovalº.
5. Remove timing chain. Refer to EM-23, ªRemovalº.
SEM964F
6. Remove intake manifold in reverse order of installation. Refer
to ªTIGHTENING PROCEDURESº, EM-12.
7. Remove water outlet.
SEM442G
8. Remove rear timing chain case bolts.
ILoosen in numerical order as shown in the figure.
SEM168FA
9. Remove rear timing chain case.
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CYLINDER HEAD
Components (Cont'd)
EM-39

SEM532G
3. Before installing the cylinder head gasket, be sure that No. 1
cylinder is at TDC.
IAt this time, the crankshaft key should face toward the right
bank.
SEM445G
4. Install cylinder heads with new gaskets.
IDo not rotate crankshaft and camshaft separately, or
valves will strike piston heads.
SEM957E
CAUTION:
Cylinder head bolts are tightened by plastic zone tightening
method. Whenever the size difference between d1 and d2
exceeds the limit, replace them with new ones.
Limit (d1 - d2):
0.11 mm (0.0043 in)
ILubricate threads and seat surfaces of the bolts with new
engine oil.
CYLINDER HEAD
Installation (Cont'd)
EM-48

SEM653F
IIdentification marks are present on camshafts.
Bank INT/EXH ID mark Drill markPaint mark
M1 M2
RHINT R3 Yes Yes No
EXH R3 No No Yes
LHINT L3 Yes Yes No
EXH L3 No No Yes
SEM533G
IPosition camshaft
RH exhaust camshaft dowel pin at about 10 o'clock
LH exhaust camshaft dowel pin at about 2 o'clock
SEM564G
SEM446G
8. Before installing camshaft brackets, apply sealant to mating
surface of No. 1 journal head.
IUse Genuine RTV silicone sealant Part No. 999MP-A7007
or equivalent.
IRefer to ªPOSITION FOR APPLYING LIQUID GASKETº,
EM-21.
IInstall camshaft brackets in their original positions.
Align stamp mark as shown in the figure.
IIf any part of valve assembly or camshaft is replaced,
check valve clearance according to reference data.
After completing assembly check valve clearance. Refer
to ªCheckingº and ªAdjustingº in ªVALVE CLEARANCEº,
EM-52 and 54.
Reference data valve clearance (Cold):
Intake
0.26 - 0.34 mm (0.010 - 0.013 in)
Exhaust
0.29 - 0.37 mm (0.011 - 0.015 in)
ILubricate threads and seat surfaces of camshaft bracket
bolts with new engine oil before installing them.
CYLINDER HEAD
Installation (Cont'd)
EM-50

12. Apply sealant to the hatched portion of rear timing chain case.
IApply continuous bead of liquid gasket to mating surface of
rear timing chain case.
Refer to ªPOSITION FOR APPLYING LIQUID GASKETº,
EM-21.
IBefore installation, wipe off the protruding sealant.
SEM448G
13. Align rear timing chain case with dowel pins, then install on
cylinder head and block.
14. Tighten rear chain case bolts.
a. Tighten bolts in numerical order shown in the figure.
b. Repeat above step a.
15. Reinstall all removed parts in reverse order of removal.
SEM868E
Valve ClearanceNBEM0022CHECKINGNBEM0022S01Check valve clearance while engine is cold and not running.
1. Remove engine cover.
2. Remove air duct with air cleaner case, collectors, hoses, wires,
harnesses, connectors and so on.
3. Remove intake manifold collectors.
4. Remove ignition coils and spark plugs.
5. Remove RH and LH rocker covers.
6. Set No. 1 cylinder at TDC on its compression stroke.
IAlign pointer with TDC mark on crankshaft pulley.
CYLINDER HEAD
Installation (Cont'd)
EM-52