Fuel system INFINITI QX56 2008 Factory Service Manual

EM-4
< PRECAUTION >
PRECAUTIONS
5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of a ll control units using CONSULT-III.
Precaution for Drain Engine CoolantINFOID:0000000001538794
Drain engine coolant when engine is cooled.
Precaution for Disconnecting Fuel PipingINFOID:0000000001538795
• 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:0000000001538796
• When instructed to use special service tools, use the s pecified 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 equivalent, 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, start 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:0000000001538797
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precaution for Assembly and InstallationINFOID:0000000001538798
• 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 theones 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.
• 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:0000000001538799
• 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. Tool number : KV10112100 (BT-8653-A)
Revision: March 2010
2008 QX56

EM-30
< ON-VEHICLE REPAIR >
EXHAUST MANIFOLD AND THREE WAY CATALYST
EXHAUST MANIFOLD AND THREE WAY CATALYST
Exploded ViewINFOID:0000000006055156
Removal and InstallationINFOID:0000000006055157
REMOVAL
WARNING:
Perform the work when the exhaust and cooling system have cooled sufficiently.
1. Remove the engine undercover (rear) using power tool (4WD models).
2. Remove front final drive assembly (4WD models). Refer to DLN-212, "
Removal and Installation".
3. Remove the main muffler assembly and center exhaust tube. Refer to EX-6, "
Removal and Installation".
4. Remove the front exhaust tubes. Refer to EX-6, "
Removal and Installation".
5. Remove front tires. Refer to WT-48, "
Rotation".
6. Remove fender protectors. Refer to EXT-23, "
Removal and Installation".
7. Remove the LH and RH air fuel ratio A/F sensors. • Follow steps below to remove each air fuel ratio A/F sensor.
a. Remove the harness connector of each air fuel ra tio A/F sensor, and harness from bracket and middle
clamp.
1. Air fuel ratio A/F sensor 1 (bank 2) 2. Exhaust manifold cover (bank 2) 3. Exhaust manifold (bank 2)
4. Gaskets 5. Exhaust manifold (bank 1) 6. Exhaust manifold cover (bank 1)
7. Air fuel ratio A/F sensor 1 (bank 1) A. Up B. Coated face
C. Manifold side D. Up mark Front
AWBIA0453GB
Revision: March 2010 2008 QX56

EM-32
< ON-VEHICLE REPAIR >
EXHAUST MANIFOLD AND THREE WAY CATALYST
• Install new exhaust manifold gasket with the top of the triangularup mark on it facing up and its coated face (gray side) toward the
exhaust manifold side.
• Tighten the exhaust manifold nuts LH and RH in the numerical order shown. Then recheck the torque of the nuts.
- A: Exhaust manifold (LH)
- B: Exhaust manifold (RH)
- : Front
• Before installing new air fuel ratio A/F sensors, clean the exhaust system threads using suitable tool and
apply anti-seize lubricant.
CAUTION:
• Do not over tighten the air fuel ratio A/F se nsors. Doing so may cause damage to the sensor,
resulting in the MIL coming on.
KBIA2553E
AWBIA0814ZZ
Oxygen sensor thread cleaner : (J-43897-12)
Oxygen sensor thread cleaner : (J-43897-18)
Revision: March 2010 2008 QX56

EM-52
< ON-VEHICLE REPAIR >
TIMING CHAIN
a. Apply engine oil onto the threaded parts of the bolt and seating area.
b. Select the one most visible notch of the four on the bolt flange.Corresponding to the selected notch, put a alignment mark
(such as paint) on the crankshaft pulley.
14. Rotate the crankshaft pulley in normal direction (clockwise when viewed from engine front) to check for parts interference.
15. Installation of the remaining components is in the reverse of order of removal.
INSPECTION AFTER INSTALLATION
• Before starting engine, check oil/fluid levels incl uding engine coolant and engine oil. If less than required
quantity, fill to the specified level. Refer to MA-12, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak- age at connection points.
• Start engine. With engine speed increased, che ck again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
• Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids including
engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec-
ified level, if necessary.
• Summary of the inspection items:
*Power steering fluid, brake fluid, etc.
Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90 ° (angle tightening)
KBIA2519E
Item Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Transmission/
transaxle fluid A/T and CVT Models
LeakageLevel/Leakage Leakage
M/T Models Level/Leakage LeakageLevel/Leakage
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakage Leakage
Exhaust gas —Leakage —
Revision: March 2010 2008 QX56

CYLINDER HEADEM-69
< ON-VEHICLE REPAIR >
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• Cylinder head bolts are tightened by plastic zone tightening
method. Whenever the size difference between d1 and d2 exceeds
the limit, replace the bolt with a new one.
• If reduction of diameter appears in a position other than d2, use it as d2 point.
INSTALLATION
1. Install a new cylinder head gasket.
2. Install the cylinder head. Follow the steps below to tighten the bolts in the numerical order shown.
CAUTION:
• If cylinder head bolts are re-used, check their diameters
before installation. Refer to "Cylinder Head Bolts Diame-
ter".
a. Apply engine oil to threads and seating surface of the bolts.
b. Measure the tightening angle using Tool. CAUTION:
Measure the tightening angl e using Tool. Do not measure
visually.
3. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
• Before starting engine, check oil/fluid levels incl uding engine coolant and engine oil. If less than required
quantity, fill to the specified level. Refer to MA-12, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak-
age at connection points.
• Start engine. With engine speed increased, check again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
• Warm up engine thoroughly to make sure there is no leak age of fuel, exhaust gas, or any oils/fluids including
engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec- ified level, if necessary.
• Summary of the inspection items: Limit (d1 - d2) : 0.23 mm (0.0091 in)
KBIA0189E
PBIC0068E
Step a : 44.1 N·m (4.5 kg-m, 33 ft-lb)
Step b : 70°
clockwise
Step c : Loosen in the reverse order of tightening.
Step d : 44.1 N·m (4.5 kg-m, 33 ft-lb)
Step e : 60 ° clockwise
Step f : 60° clockwise
WBIA0603E
Tool number : KV10112100 (BT-8653-A)
Revision: March 2010 2008 QX56

EM-78
< REMOVAL AND INSTALLATION >
ENGINE ASSEMBLY
REMOVAL AND INSTALLATION
ENGINE ASSEMBLY
Removal and InstallationINFOID:0000000001538831
WARNING:
• Situate vehicle on a flat and solid surface.
• Place chocks at front and back of rear wheels.
• For engines not equipped with engine slingers, attach proper slingers and bolts described in PARTS
CATALOG.
CAUTION:
• Always be careful to work safely, avoid forceful or uninstructed operations.
• Do not start working until exh aust system and engine coolant are cooled sufficiently.
• If items or work required are no t covered by the engine section, follow the applicable procedures.
• Always use the support poin t specified for lifting.
• Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,
support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.
• For supporting points for lifting and jacking point at rear axle, refer to GI-30, "
Garage Jack and
Safety Stand".
REMOVAL
Preparation
1. Drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
2. Partially drain the A/T fluid. Refer to TM-180, "
Changing the A/T Fluid (ATF)".
3. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
1. Rear engine mounting insulator 4WD 2. Rear engine mounting insulator 2WD 3. LH engine mounting bracket
4. LH heat shield plate 5. LH engine mounting insulator 6. RH engine mounting bracket
7. RH heat shield plate 8. RH engine mounting insulator
LBIA0397E
Revision: March 2010 2008 QX56

ENGINE ASSEMBLYEM-81
< REMOVAL AND INSTALLATION >
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• Start engine. With engine speed increased, check again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
• Warm up engine thoroughly to make sure there is no leak
age of fuel, exhaust gas, or any oils/fluids including
engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec- ified level, if necessary.
• Summary of the inspection items:
*Power steering fluid, brake fluid, etc. Item
Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Transmission/
transaxle fluid A/T and CVT Models
LeakageLevel/Leakage Leakage
M/T Models Level/Leakage LeakageLevel/Leakage
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakageLeakage
Exhaust gas —Leakage —
Revision: March 2010 2008 QX56

FL-1
ENGINE
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SECTION FL
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FL
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CONTENTS
FUEL SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
FUEL SYSTEM ....................................................4
General Precaution ............................................. ......4
PREPARATION ............................................5
PREPARATION .............................................. .....5
Special Service Tool ........................................... ......5
Commercial Service Tool ..........................................5
BASIC INSPECTION ....................................6
FUEL SYSTEM ............................................... .....6
Checking Fuel Line ............................................. ......6
REMOVAL AND INSTALLATION ................7
FUEL LEVEL SENSOR UNIT, FUEL FILTER
AND FUEL PUMP ASSEMBLY .........................
7
Removal and Installation ..................................... .....7
FUEL TANK ......................................................11
Removal and Installation ..................................... ....11
DISASSEMBLY AND ASSEMBLY ..............16
FUEL LEVEL SENSOR UNIT, FUEL FILTER
AND FUEL PUMP ASSEMBLY ........................
16
Disassembly and Assembly ................................. ....16
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
17
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
17
Standard and Limit .............................................. ....17
Revision: March 2010 2008 QX56

FL-4
< PRECAUTION >
FUEL SYSTEM
FUEL SYSTEM
General PrecautionINFOID:0000000001534428
WARNING:
When replacing fuel line parts, be sure to observe the following.
• Put a “CAUTION: INFLAMMABLE” sign in the workshop.
• Be sure to work in a well ventilate d area and furnish workshop with a CO
2 fire extinguisher.
• Do not smoke while servicing fuel system. Keep open flames and sparks away from the work area.
CAUTION:
• Before removing fuel line parts, carry out the following procedures:
- Put drained fuel in an explosi on-proof container and put the lid on securely. Keep the container in
safe area.
- Release fuel pressure from the fuel lines. Refer to EC-494, "
Fuel Pressure Check" .
- Disconnect the battery negative terminal.
• Always replace O-rings and clamps with new ones.
• Do not kink or twist hoses when they are being installed.
• After connecting the fuel t ube quick connectors, make sure
the quick connectors are secure.
Ensure that the connector and resin tube do not contact any
adjacent parts.
• After installing tubes, make su re there is no fuel leakage at
connections in the following steps.
- Apply fuel pressure to fuel lines with turning ignition switch
ON (with engine stopped). Th en check for fuel leaks at con-
nections.
- Start the engine and rev it up and check for fuel leaks at con-
nections.
• Use only a Genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used, the MIL may come on.
• For servicing “Evaporative Emission System” parts, refer to EC-498, "
Removal and Installation" .
• For servicing “On Board Refueling Vapor Recovery (ORVR)”
parts, refer to EC-496, "
How to Detect Fuel Vapor Leakage" .
PBIC1268E
Revision: March 2010 2008 QX56

FL-6
< BASIC INSPECTION >
FUEL SYSTEM
BASIC INSPECTION
FUEL SYSTEM
Checking Fuel LineINFOID:0000000001534429
Inspect fuel lines, fuel filler cap and fuel tank for improper attach-
ment, leaks, cracks, damage, loose connections, chafing or deterio-
ration.
If necessary, repair or replace damaged parts.
SMA803A
Revision: March 20102008 QX56