EC-526
< SYMPTOM DIAGNOSIS >[VK56VD]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Manifold absolute pressure sensor circuit 3
EC-210
Battery current sensor 4 5 5 3EC-412EC-420
EC-424
Heated oxygen sensor 2 6 6 6 6 5EC-243EC-249
EC-257
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank 5
5 FL-4
Fuel piping 555 55 5
FL-4
Vapor lock —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gasoline,
Low octane) —
Revision: 2010 May2011 QX56
ENGINE CONTROL SYSTEM SYMPTOMSEC-527
< SYMPTOM DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Air Air duct
55555 5 EM-28
Air cleaner
EM-27
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-28
Electric throttle control actuator
EC-460
Air leakage from intake manifold/
Collector/GasketEM-30
Cranking Battery
111111
11
PG-161
Generator circuit
CHG-13
Starter circuit 3STR-11
Signal plate 6EM-106
PNP signal 4EC-383
Engine Cylinder head
55555 55 5 EM-92
Cylinder head gasket 4 3
Cylinder block
66666 66 6 4
EM-115
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-72
Camshaft
EM-77
Intake valve timing controlEM-61
Intake valve
3EM-92
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/ Gasket 55555 55 5 EM-42
EX-6Three way catalystSYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: 2010 May2011 QX56
EM-2
Removal and Installation ........................................30
ROCKER COVER ..............................................33
Exploded View ..................................................... ...33
Removal and Installation ........................................33
VVEL ACTUATOR ASSEMBLY ........................36
Exploded View ..................................................... ...36
Removal and Installation ........................................36
Inspection ...............................................................39
EXHAUST MANIFOLD AND THREE WAY
CATALYST ........................................................
40
Exploded View ..................................................... ...40
Removal and Installation ........................................40
Inspection ...............................................................42
HIGH PRESSURE FUEL PUMP AND FUEL
HOSE .................................................................
43
Exploded View ..................................................... ...43
Removal and Installation ........................................43
Inspection ...............................................................46
FUEL INJECTOR AND FUEL TUBE .................48
Exploded View ..................................................... ...48
Removal and Installation ........................................49
Inspection ...............................................................53
OIL PAN (LOWER) AND OIL STRAINER .........54
Exploded View ..................................................... ...54
Removal and Installation ........................................55
Inspection ...............................................................56
OIL PAN (UPPER) .......................................... ...57
Exploded View ..................................................... ...57
Removal and Installation ........................................58
Inspection ...............................................................60
TIMING CHAIN ............................................... ...61
Exploded View ..................................................... ...61
Removal and Installation ........................................62
Inspection ...............................................................72
CAMSHAFT .......................................................74
Exploded View ..................................................... ...74
Removal and Installation ........................................75
Inspection ...............................................................77
CYLINDER HEAD ..............................................86
Exploded View ..................................................... ...86
Removal and Installation ........................................87
Disassembly and Assembly ....................................89
Inspection ............................................................. ...92
OIL SEAL ...........................................................96
FRONT OIL SEAL .................................................. ...96
FRONT OIL SEAL : Removal and Installation ........96
REAR OIL SEAL .................................................... ...96
REAR OIL SEAL : Removal and Installation ...........97
UNIT REMOVAL AND INSTALLATION ....98
ENGINE ASSEMBL Y ..................................... ...98
Exploded View ..................................................... ...98
Removal and Installation .........................................99
Inspection ..............................................................102
UNIT DISASSEMBLY AND ASSEMBLY ..103
ENGINE STAND SETTING ..............................103
Setting .................................................................. .103
ENGINE UNIT ...................................................105
Disassembly ......................................................... .105
Assembly ..............................................................105
CYLINDER BLOCK ..........................................106
Exploded View ..................................................... .106
Disassembly and Assembly ..................................107
Inspection ..............................................................115
HOW TO SELECT PISTON AND BEARING ...125
Description ........................................................... .125
Piston ....................................................................125
Connecting Rod Bearing .....................................126
Main Bearing ........................................................128
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
132
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
132
General Specification .......................................... .132
Drive Belts .............................................................132
Spark Plug ............................................................132
Exhaust Manifold ..................................................133
Camshaft ...............................................................133
Cylinder Head ......................................................135
Cylinder Block ......................................................137
Main Bearing ........................................................141
Connecting Rod Bearing .....................................142
Revision: 2010 May2011 QX56
PRECAUTIONSEM-3
< PRECAUTION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
PRECAUTION
PRECAUTIONS
Precaution for Procedur
e without Cowl Top CoverINFOID:0000000006289506
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006417202
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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 AIR BAG”.
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.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006289508
NOTE:
Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
PIIB3706J
Revision: 2010 May2011 QX56
EM-4
< PRECAUTION >
PRECAUTIONS
If turning the steering wheel is required with the battery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables.
NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
5. When the repair work is completed, re-connect bot h battery cables. With the brake pedal released, turn
the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering
wheel will lock when the push-button igniti on switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.
Precaution for Drain Engine Coolant and Engine OilINFOID:0000000006289509
Drain engine coolant and engine oil when engine is cooled.
Precaution for Disconnecting Fuel PipingINFOID:0000000006289510
Before starting work, check no fire or sp ark 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 Handling High Pressure Fuel SystemINFOID:0000000006289511
High pressure fuel system components are betw een high pressure fuel pump and fuel injector.
Always release fuel pressure and never start the engine when performing removal and installation.
When removing or installing parts without releasing fuel pressure, fuel may be splashed and, if fuel contacts
skin or eyes, it may cause inflammation.
Precaution for Removal and DisassemblyINFOID:0000000006289512
When instructed to use SST, use specified tools. Always be careful to work safely, avoid forceful or unin-
structed operations.
Exercise maximum care to avoid damage to mating or sliding surfaces.
Cover openings of engine system with tape or the equival ent, if necessary, to seal out foreign materials.
Mark and arrange disassembly parts in an organi zed way for easy troubleshooting and assembly.
When loosening nuts and bolts, as a basic rule, star t with the one furthest outside, then the one diagonally
opposite, and so on. If the order of loosening is specified, do exactly as specified. Power tools may be used
where noted in the step.
Precaution for Inspection, Repair and ReplacementINFOID:0000000006289513
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precaution for Assembly and InstallationINFOID:0000000006289514
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.
Dowel pins are used for several parts alignment. When replacing and reassembling parts with dowel pins,
check that dowel pins are installed in the original position.
Revision: 2010 May2011 QX56
CAMSHAFT VALVE CLEARANCEEM-13
< BASIC INSPECTION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
a. Set No. 1 cylinder at TDC of its compression stroke.
Rotate crankshaft pulley clockwise to align timing mark
(grooved line without color) (B) with timing indicator (A).
Check that exhaust cam nose on No. 1 cylinder (engine front side of bank 1) is located as shown in the figure.
If not, turn crankshaft one revolution (360 degrees) and align as shown in the figure.
By referring to the figure, measure the valve clearances at locations marked “ ×” as shown in the table below (locations
indicated in the figure).
No. 1 cylinder at compression TDC
NOTE:
JPBIA2070ZZ
1 : Exhaust camshaft (bank 1) : Engine front
JPBIA2071ZZ
: Engine front
Measuring position [bank 2 (A)] No. 2
CYL. No. 4
CYL. No. 6
CYL. No. 8
CYL.
No. 1 cylinder at com- pression TDC EXH
× (C)
INT × (D) × (E)
Measuring position [bank 1 (B)] No. 1
CYL. No. 3
CYL. No. 5
CYL. No. 7
CYL.
No. 1 cylinder at com- pression TDC INT
× (F) × (G)
EXH × (H) × (I)
JPBIA3488ZZ
Revision: 2010 May2011 QX56
EM-14
< BASIC INSPECTION >
CAMSHAFT VALVE CLEARANCE
To measure valve clearance of No. 1 cylinder INT valve (front
side), insert feeler gauge (A) (commercial service tool) as shown
in the figure.
b. Rotate crankshaft 270 degrees clockwise (when viewed from engine front) to align No. 3 cylinder at TDC its compression stroke.
NOTE:
Crankshaft pulley mounting bolt flange has an angle mark (B)
every 90 degrees (c). They can be used as a guide to rotation
angle.
By referring to the figure, measure the valve clearances atlocations marked “ ×” as shown in the table below (locations
indicated in the figure).
No. 3 cylinder at compression TDC
c. Rotate crankshaft 90 degrees clockwise (when viewed from engine front) to align No. 6 cylinder at TDC of compression stroke.
NOTE:
: Engine front
JPBIA3489ZZ
A : Paint mark
JPBIA2066ZZ
: Engine front
Measuring position [bank 2 (A)] No. 2
CYL. No. 4
CYL. No. 6
CYL. No. 8
CYL.
No. 3 cylinder at com- pression TDC EXH
× (C)
INT × (D)
Measuring position [bank 1 (B)] No. 1
CYL. No. 3
CYL. No. 5
CYL. No. 7
CYL.
No. 3 cylinder at com- pression TDC INT
× (E) × (F)
EXH × (G) × (H)
JPBIA3490ZZ
Revision: 2010 May2011 QX56
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGEM-19
< SYMPTOM DIAGNOSIS >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
Use the Chart Below to Help You Find the Cause of the SymptomINFOID:0000000006289523
1. Locate the area where noise occurs.
2. Confirm the type of noise.
3. Specify the operating condition of the engine.
4. Check specified noise source.
If necessary, repair or replace these parts.
A: Closely related B: Related C: Sometimes related —: Not related Location
of noise Type of
noise Operating condition of engine
Source of noise Check item Refer-
ence page
Before
warm- up After
warm- up When
start- ing When
idling When
racing While
driving
Top of en-
gine
Rocker
cover
Cylinder
head Ticking or
clicking
CA—AB— Tappet
noiseValve clearance
EM-12
Rattle C A — A B C Camshaft
bearing
noiseCamshaft runout
Camshaft journal oil
clearance
EM-77
Crank-
shaft pul-
ley
Cylinder
block
(Side of
engine)
Oil panSlap or
knock
—A—B B—
Piston pin
noisePiston to piston pin oil
clearance
Connecting rod bushing
oil clearance
EM-115
Slap or
rap
A——B B A
Piston
slap noisePiston to cylinder bore
clearance
Piston ring side clear-
ance
Piston ring end gap
Connecting rod bend
and torsion
EM-115
Knock A B C B B B
Connect-
ing rod
bearing
noiseConnecting rod bushing
oil clearance
Connecting rod bearing
oil clearance
EM-115
Knock A B — A B C
Main bear-
ing noiseMain bearing oil clear-
ance
Crankshaft runout
EM-115
Front of
engine
Timing
chain caseTapping or
ticking
AA—BBB Timing
chain and
timing
chain ten-
sioner
noiseTiming chain cracks
and wears
Timing chain tensioner
operation
EM-72
Front of
engineSqueak-
ing or fizz-
ing
AB—B—C Drive belts
(Sticking
or slip-
ping)Drive belts deflection
EM-20
CreakingABABAB Drive belts
(Slipping)Idler pulley bearing op-
eration
Squall
Creak AB—BAB Water
pump
noiseWater pump operation
CO-19
Revision: 2010 May2011 QX56