2007 INFINITI QX56 engine

FRONT BUMPER
EI-13
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• Disconnect harnesses.
5. Remove engine undercover.
6. Remove fasteners, release clips and remove front fascia assembly.
7. Remove plastic clips and remove upper energy absorber.
8. Remove upper bumper reinforcement.
9. Remove plastic clips and remove lower energy absorber.
10. Remove front bumper stays and front bumper side brackets, LH and RH.
INSTALLATION
Installation is in the reverse order of removal.

EM-1
ENGINE
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SECTION EM
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CONTENTS
ENGINE MECHANICAL
SERVICE INFORMATION .. ..........................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution for Drain Engine Coolant .........................3
Precaution for Disconnecting Fuel Piping .................3
Precaution for Removal and Disassembly ................3
Precaution for Inspection, Repair and Replace-
ment .................................................................... ......
3
Precaution for Assembly and Installation ..................3
Parts Requiring Angular Tightening ..........................4
Precaution for Liquid Gasket ............................... ......4
PREPARATION ...................................................6
Special Service Tool ........................................... ......6
Commercial Service Tool ..........................................8
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ............................
10
NVH Troubleshooting - Engine Noise ................. ....10
Use the Chart Below to Help You Find the Cause
of the Symptom .......................................................
11
ENGINE ROOM COVER ....................................12
Removal and Installation .........................................12
DRIVE BELTS ................................................ ....13
Checking Drive Belts ........................................... ....13
Removal and Installation .........................................13
Drive Belt Auto Tensioner and Idler Pulley ......... ....14
AIR CLEANER AND AIR DUCT ........................15
Removal and Installation .........................................15
Removal and Installation (Viscous paper type) ... ....15
INTAKE MANIFOLD ...........................................17
Removal and Installation .........................................17
EXHAUST MANIFOLD AND THREE WAY
CATALYST ..................................................... ....
21
Removal and Installation ..................................... ....21
OIL PAN AND OIL STRAINER .........................24
Removal and Installation .........................................24
IGNITION COIL .................................................28
Removal and Installation .........................................28
SPARK PLUG ...................................................29
Removal and Installation .........................................29
FUEL INJECTOR AND FUEL TUBE ................31
Removal and Installation .........................................31
ROCKER COVER .............................................35
Removal and Installation .........................................35
TIMING CHAIN ..................................................37
Exploded View ..................................................... ....37
Removal and Installation .........................................38
CAMSHAFT .......................................................46
Removal and Installation .........................................46
Inspection after Installation ......................................55
Valve Clearance .................................................. ....56
OIL SEAL ..........................................................61
Removal and Installation of Valve Oil Seal ..............61
Removal and Installation of Front Oil Seal ..............61
Removal and Installation of Rear Oil Seal ...............62
CYLINDER HEAD .............................................64
On-Vehicle Service .............................................. ....64
Removal and Installation .........................................65
Disassembly and Assembly .....................................67
Inspection After Disassembly ..................................69
ENGINE ASSEMBLY ........................................74
Removal and Installation ..................................... ....74
CYLINDER BLOCK ...........................................78
Disassembly and Assembly .....................................78
How to Select Piston and Bearing ....................... ....86

PRECAUTIONSEM-3
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SERVICE INFORMATION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003531508
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
Precaution for Drain Engine CoolantINFOID:0000000003531509
Drain engine coolant when engine is cooled.
Precaution for Disco nnecting Fuel PipingINFOID:0000000003531510
• Before starting work, make sure no fire or spark producing items are in the work area.
• Release fuel pressure before disconnecting and disassembly.
• After disconnecting pipes, plug openings to stop fuel leakage.
Precaution for Removal and DisassemblyINFOID:0000000003531511
• When instructed to use special service tools, use the spec ified tools. Always be careful to work safely, avoid
forceful or uninstructed operations.
• Exercise maximum care to avoid damage to mating or sliding surfaces.
• Cover openings of engine system with tape or the equiva lent, if necessary, to seal out foreign materials.
• Mark and arrange disassembly parts in an organized way for easy troubleshooting and assembly.
• When loosening nuts and bolts, as a basic rule, start with the one furthest outside, then the one diagonally
opposite, and so on. If the order of loosening is specif ied, do exactly as specified. Power tools may be used
where noted in the step.
Precaution for Inspection, Repair and ReplacementINFOID:0000000003531512
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precaution for Assembly and InstallationINFOID:0000000003531513
• Use torque wrench to tighten bolts or nuts to specification.
• When tightening nuts and bolts, as a basic rule, equally tighten in several different steps starting with the ones in center, then ones on inside and outside diagonally in this order. If the order of tightening is specified,
do exactly as specified.
• Replace with new gasket, packing, oil seal or O-ring.
• Thoroughly wash, clean, and air-blow each part. Carefully check engine oil or engine coolant passages for any restriction and blockage.
• Avoid damaging sliding or mating surfaces. Completely remove foreign materials such as cloth lint or dust. Before assembly, oil sliding surfaces well.

EM-4
< SERVICE INFORMATION >
PRECAUTIONS
• Release air within route when refilling after draining engine coolant.
• Before starting engine, apply fuel pressure to fuel lines with turning ignition switch ON (with engine stopped).
Then make sure that there are no leaks at fuel line connections.
• After repairing, start engine and increase engine s peed to check engine coolant, fuel, oil, and exhaust sys-
tems for leakage.
Parts Requiring Angular TighteningINFOID:0000000003531514
• For final tightening of the following engine parts use Tool:
- Cylinder head bolts
- Main bearing cap bolts
- Connecting rod cap bolts
- Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angle tightening)
• Do not use a torque value for final tightening.
• The torque value for these parts are for a preliminary step.
• Ensure thread and seat surfaces are clean and lightly coated with engine oil.
Precaution for Liquid GasketINFOID:0000000003531515
REMOVAL OF LIQUID GASKET SEALING
• After removing the bolts and nuts, separate the mating surface and
remove the old liquid gasket sealing using Tool.
CAUTION:
Do not damage the mating surfaces.
• Tap the seal cutter to insert it.
• In areas where the Tool is difficult to use, lightly tap to slide it.
LIQUID GASKET APPLICATION PROCEDURE
1. Remove the old liquid gasket adhering to the gasket application surface and the mating surface using suitable tool.
• Remove the liquid gasket completely from the groove of theliquid gasket application surface, bolts, and bolt holes.
2. Thoroughly clean the mating surfaces and remove adhering moisture, grease and foreign material.
3. Attach the liquid gasket tube to the Tool. Use Genuine RTV Silicone Seal ant or equivalent. Refer to
GI-45, "
Recommended Chemical Product and Sealant".
4. Apply the liquid gasket without breaks to the specified location with the specified dimensions.Tool number : KV10112100 (BT-8653-A)
Tool number : KV10111100 (J-37228)
WBIA0566E
PBIC0003E
Tool number : WS39930000 ( — )
WBIA0567E

PRECAUTIONSEM-5
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• If there is a groove for the liquid gasket application, apply the
liquid gasket to the groove.
• As for the bolt holes, normally apply the liquid gasket inside
the holes. If specified in t he procedure, it should also be
applied outside the holes.
• Within five minutes of liquid gasket application, install the mat-
ing component.
• If the liquid gasket protrudes, wipe it off immediately.
• Do not retighten after the installation.
• Wait 30 minutes or more after installation before refilling the
engine with engine oil and engine coolant.
CAUTION:
If there are specific instructions in this manual, observe them.
SEM159F

EM-10
< SERVICE INFORMATION >
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting - Engine NoiseINFOID:0000000003586490
AWBIA0149ZZ
1. Timing chain 2. Intake valve 3. Exhaust valve
4. Drive belt 5. Water pump A. VTC noise

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGEM-11
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Use the Chart Below to Help You
Find the Cause of the SymptomINFOID:0000000003531519
1. Locate the area where noise occurs.
2. Confirm the type of noise.
3. Specify the operating condition of engine.
4. Check specified noise source.
If necessary, repair or replace these parts.
A: Closely related B: Related C: Sometimes related —: Not relatedB. Tappet noise C. Camshaft bearing noise D. Valve mechanism
E. Rotation mechanism F. Piston pin noise G. Piston slap noise
H. Main bearing noise I. Connecting rod bearing noise J. Drive belt noise (slipping)
K. Drive belt noise (stick/slipping) L. Water pump noise M. Timing chain and chain tensioner noise
Location of noise Ty p e o f
noise Operating condition of engine
Source of noise Check item
Refer-
ence page
Be-
fore
warm- up After
warm-
up When
start-
ing When
idling When
racing While
driv-
ing
Top of en-
gine
Rocker cov-
er
Cylinder
head Ticking or
clicking
C A — A B — Tappet noise Valve clearance
EM-56
Rattle C A — A B CCamshaft
bearing noiseCamshaft journal clear-
ance
Camshaft runout EM-46EM-46
Crankshaft
pulley
Cylinder
block (Side
of engine)
Oil panSlap or
knock
—A—B B— Piston pin
noisePiston and piston pin
clearance
Connecting rod bushing
clearance EM-93
EM-93
Slap or
rap
A——B B A Piston slap
noisePiston-to-bore clear-
ance
Piston ring side clear-
ance
Piston ring end gap
Connecting rod bend
and torsion EM-93EM-93
EM-93
EM-93
Knock A B C B B B
Connecting
rod bearing
noiseConnecting rod bushing
oil clearance (Small
end)
Connecting rod bearing
clearance (Big end)
EM-93EM-93
Knock A B — A B C
Main bearing
noiseMain bearing oil clear-
ance
Crankshaft runout EM-93EM-93
Front of en-
gine
Chain case
cover
Front coverTapping
or ticking
AA—BBB Timing chain
and chain
tensioner
noiseTiming chain cracks
and wear
Timing chain tensioner
operation
EM-38
EM-38
Front of en-
gineSqueak-
ing or
fizzing
AB—B—C
Drive belts
(Sticking or
slipping)Drive belts deflection
EM-13Creaking A B A B A B Drive belts
(Slipping)Idler pulley bearing op-
eration
Squall
Creaking AB—BAB Water pump
noiseWater pump operation
EM-38
Rattle — — A — — — VTC VTC lockpin clearance EM-55

EM-12
< SERVICE INFORMATION >
ENGINE ROOM COVER
ENGINE ROOM COVER
Removal and InstallationINFOID:0000000003531520
REMOVAL
• Remove the engine cover bolts and cover.CAUTION:
Do not damage or scratch cover when installing or removing.
INSTALLATION
Installation is in the reverse order of removal.
WBIA0795E