engine INFINITI QX56 2011 Factory Service Manual

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

PRECAUTIONSEM-5
< PRECAUTION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
 Avoid damaging sliding or mating surfaces. Completely re
move foreign materials such as cloth lint or dust.
Before assembly, oil sliding surfaces well.
 Release air within route when refilling after draining engine coolant.
 After repairing, start engine and increase engine speed to check engine coolant, fuel, engine oil, and
exhaust gases for leakage.
Parts Requiring Angle TighteningINFOID:0000000006289515
 Use angle wrench [SST: KV10112100 (BT8653-A)] for the final tightening of the following engine parts:
- Cylinder head bolts
- Main bearing cap bolts
- Main bearing cap sub bolts
- Connecting rod cap bolts
- Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angletightening)
 Ensure thread and seat surfaces are clean and coated with engine oil.
Precaution for Liquid GasketINFOID:0000000006289516
REMOVAL OF LIQUID GASKET SEALING
 After removing mounting nuts and bolts, separate the mating sur- face using the seal cutter [SST:KV10111100 (J-37228)] (A) and
remove old liquid gasket sealing.
CAUTION:
Be careful not to damage the mating surfaces.
 Tap the seal cutter to insert it (B), and then slide it (C) by tapping on the side as shown in the figure.
 In areas where the seal cutter is difficult to use, lightly tap the parts using a plastic hammer to remove it.
CAUTION:
If for some unavoidable reason a tool such as a screwdriver is
used, be careful not to damage the mating surfaces.
LIQUID GASKET APPLICATION PROCEDURE
1. Using a scraper (A), remove old liquid gasket adhering to the liq- uid gasket application surface and the mating surface.
 Remove liquid gasket completely from the groove of the liquidgasket application surface, mounting bolts and bolt holes.
2. Wipe the liquid gasket application surface and the mating sur- face with white gasoline (lighting and heating use) to remove
adhering moisture, grease and foreign materials.
3. Attach liquid gasket tube to the tube presser (commercial ser- vice tool).
Use Genuine RTV Silicone Seal ant or equivalent. Refer to
GI-22, "
Recommended Chemical Products and Sealants".
4. Apply liquid gasket without gaps to the specified location accord- ing to the specified dimensions.
 If there is a groove for liquid gasket application, apply liquidgasket to the groove.
JPBIA0052ZZ
JPBIA0053ZZ
EMA0622D
Revision: 2010 May2011 QX56

EM-6
< PRECAUTION >
PRECAUTIONS
 As for bolt holes (B), normally apply liquid gasket inside theholes. Occasionally, it should be applied outside the holes.
Check to read the text of this manual.
 Within 5 minutes of liquid gasket application, install the mating component.
 If liquid gasket protrudes, wipe it off immediately.
 Do not retighten mounting bolts or nuts after the installation.
 After 30 minutes or more have passed from the installation, fill
engine oil and engine coolant.
CAUTION:
If there are specific instructions in this manual, observe them.
Definitions of Bank NamesINFOID:0000000006289517
 In this manual, each bank name is defined as per the following:
 For cylinder numbers and bank layout, refer to the figure.
A: Groove
: Inside
JPBIA0010ZZ
A : Bank 2 (The conventional right bank)
B : Bank 1 (The conventional left bank)
: Engine front
Bank 1 : The bank side including cylinder No. 1 (odd-numbered cylinder side)
Bank 2 : The other bank side of the above (even-numbered cylinder side)
JPBIA2064ZZ
Revision: 2010 May2011 QX56

PREPARATIONEM-9
< PREPARATION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
Commercial Service ToolINFOID:0000000006289519
KV101197S0
(—)
Injector seal drift set
Installing fuel injector seal ring
EG15050500
(J-45402)
Compression gauge adapter Checking compresion pressure
Tool number
(Kent-Moore No.)
Tool name
Description
JPBIA3281ZZ
ZZA1225D
(Kent-Moore No.)
Tool name
Description
(—)
Tube presser Pressing the tube of liquid gasket
(—)
Power tool Loosening nuts and bolts
(—)
Spark plug wrench Removing and installing spark plug
a: 14 mm (0.55 in)
(—)
Manual lift table caddy Removing and installing engine
S-NT052
PBIC0190E
JPBIA0399ZZ
ZZA1210D
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

CAMSHAFT VALVE CLEARANCEEM-15
< BASIC INSPECTION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
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 at
locations marked “ ×” as shown in the table below (locations
indicated in the figure).
 No. 6 cylinder at compression TDC
5. Perform adjustment or repl acement if the measured value is out of the standard.
 If a valve clearance on the exhaust side is out of s pecification, adjust the valve clearance. Refer to EM-
77, "Inspection".
 If a valve clearance on the intake side is out of s pecification, replace VVEL ladder assembly & cylinder
head assembly. Refer to EM-86, "
Exploded View".
CAUTION:
Never adjust valve clearance on the intake side.
NOTE:
Since the valve lifter (INT) cannot be replaced by the piece, VVEL ladder assembly & cylinder head
assembly replacement are required.
A : Paint mark
JPBIA2066ZZ
: Engine front
Measuring position [bank 2 (A)] No. 2
CYL. No. 4
CYL. No. 6
CYL. No. 8
CYL.
No. 6 cylinder at com- pression TDC EXH
× (B) × (C)
INT × (D)
JPBIA3491ZZ
Revision: 2010 May2011 QX56

EM-16
< BASIC INSPECTION >
COMPRESSION PRESSURE
COMPRESSION PRESSURE
InspectionINFOID:0000000006289521
1. Warm up engine thoroughly. Then, stop it.
2. Release fuel pressure. Refer to EC-153, "
Work Procedure".
CAUTION:
If CONSULT-III is not used to release fuel pr essure leave the fuel pump fuse disconnected until
step 7.
3. Remove fuel pump fuse in IPDM E/R. NOTE:
 For the fuse number, refer to EC-114, "
Wiring Diagram".
 For the fuse arrangement, refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
4. Remove engine cover. Refer to EM-25, "
Exploded View".
5. Remove ignition coil and spark plug from each cylinder. Refer to EM-29, "
Exploded View".
6. Connect engine tachometer (not required in use of CONSULT-III).
7. Install the compression tester with Tool [SST: EG15050500 (J- 45402)] into the spark plug hole.
8. Measure compression pressure using compressi on gauge connected with flexible type adapter (commer-
cial service tool).
9. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each
cylinder.
CAUTION:
 Measure a six-cylinder under the same conditio ns since a measurement depends on measure-
ment conditions (engine water temperature, etc.).
 Always use a fully changed battery to obtain the specified engine speed.
 If the engine speed is out of the specified range, c heck battery liquid for proper gravity. Check the
engine speed again with normal battery gravity. Refer to PG-159, "
How to Handle Battery".
 If compression pressure is below the minimum value, check valve clearances and parts associated with combustion chamber (valve, valve seat, piston, pi ston ring, cylinder bore, cylinder head, cylinder head
gasket). After checking, measure compression pressure again.
 If a cylinder has low compression pressure, pour a small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression.
- If the added engine oil improves the compression, pi ston rings may be worn out or damaged. Check pis-
ton rings and replace if necessary. Refer to EM-107, "
Disassembly and Assembly".
- If the compression pressure remains at low level despite the addition of engine oil, valves may be mal- functioning. Check valves for damage. Replace valve or valve seat accordingly. Refer to EM-107, "
Dis-
assembly and Assembly".
 If two adjacent cylinders have respectively low co mpression pressure and their compression remains
low even after the addition of engine oil, cylinder head gaskets are leaking. In such a case, replace cyl-
inder head gaskets. Refer to EM-87, "
Removal and Installation".
10. After inspection is completed, install removed parts.
11. Start the engine, and check that the engine runs smoothly.
WBIA0605E
Compression pressure : Refer to EM-132, "GeneralSpecification".
Revision: 2010 May2011 QX56

EM-18
< SYMPTOM DIAGNOSIS >
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
SYMPTOM DIAGNOSIS
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting - Engine NoiseINFOID:0000000006289522
JPBIA3483GB
Revision: 2010 May2011 QX56