2011 INFINITI QX56 fuel pressure

EM-1
ENGINE
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SECTION EM
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CONTENTS
ENGINE MECHANICAL
PRECAUTION ................ ...............................3
PRECAUTIONS .............................................. .....3
Precaution for Procedure without Cowl Top Cover ......3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
3
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
3
Precaution for Drain Engine Coolant and Engine
Oil ..............................................................................
4
Precaution for Disconnecting Fuel Piping .................4
Precaution for Handling High Pressure Fuel Sys-
tem ............................................................................
4
Precaution for Removal and Disassembly ................4
Precaution for Inspection, Repair and Replace-
ment ..........................................................................
4
Precaution for Assembly and Installation ..................4
Parts Requiring Angle Tightening .............................5
Precaution for Liquid Gasket .....................................5
Definitions of Bank Names ........................................6
PREPARATION ............................................7
PREPARATION .............................................. .....7
Special Service Tool ........................................... ......7
Commercial Service Tool ..........................................9
BASIC INSPECTION ...................................12
CAMSHAFT VALVE CLEARANCE ............... ....12
Inspection ............................................................ ....12
COMPRESSION PRESSURE ............................16
Inspection ............................................................ ....16
SYMPTOM DIAGNOSIS ..............................18
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ ....
18
NVH Troubleshooting - Engine Noise .............. ....18
Use the Chart Below to Help You Find the C
ause of the Symptom ........................................ ....
19
PERIODIC MAINTENANCE ........................20
DRIVE BELTS ...................................................20
Exploded View ..................................................... ....20
Checking ..................................................................20
Tension Adjustment ................................................20
Removal and Installation .........................................20
Inspection ................................................................21
AIR CLEANER FILTER .....................................22
Exploded View .........................................................22
Removal and Installation .........................................22
SPARK PLUG ...................................................23
Exploded View .........................................................23
Removal and Installation .........................................23
Inspection ................................................................24
REMOVAL AND INSTALLATION ...............25
ENGINE COVER ...............................................25
Exploded View ..................................................... ....25
Removal and Installation .........................................25
DRIVE BELT AUTO TENSIONER AND IDLER
PULLEY .............................................................
26
Exploded View .........................................................26
Removal and Installation .........................................26
AIR CLEANER AND AIR DUCT .......................27
Exploded View .........................................................27
Removal and Installation .........................................27
Inspection ................................................................28
IGNITION COIL .................................................29
Exploded View .........................................................29
Removal and Installation .........................................29
INTAKE MANIFOLD .........................................30
Exploded View .........................................................30
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

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

PREPARATIONEM-9
< PREPARATION >
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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

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

HIGH PRESSURE FUEL PUMP AND FUEL HOSEEM-43
< REMOVAL AND INSTALLATION >
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HIGH PRESSURE FUEL
PUMP AND FUEL HOSE
Exploded ViewINFOID:0000000006289553
CAUTION:
Never remove or disassemble parts unless instructed as shown in the figure.
Removal and InstallationINFOID:0000000006289554
REMOVAL
WARNING:
 Be sure to read EM-4, "
Precaution for Handling High Pressure Fuel System" when working on the
high pressure fuel system.
 Put a “CAUTION: FLAMMABLE” sign in the workshop.
 Be sure to work in a well ventila ted area and furnish workshop with a CO
2 fire extinguisher.
 Never smoke while servicing fuel system. Keep op en flames and sparks away from the work area.
 To avoid the danger of being scalded, never drain engine coolant when engine is hot.
1. Release fuel pressure. Refer to EC-153, "
Work Procedure".
2. Remove intake manifold. Refer to EM-30, "
Removal and Installation".
3. Disconnect harness connector from high pressure fuel pump.
1. High pressure fuel pump insulator 2. High pressure fuel pump 3. O-ring
4. Lifter 5. Fuel pump connector protector 6. Copper washer
7. Fuel feed hose 8. Copper washer 9. Low fuel pressure sensor
10. Bracket 11. Fuel feed tube (pump side)
A. From fuel tank
: Engine front
Refer to GI-4, "
Components" for symbols in the figure.
JPBIA4596GB
Revision: 2010 May2011 QX56

EM-44
< REMOVAL AND INSTALLATION >
HIGH PRESSURE FUEL PUMP AND FUEL HOSE
4. Remove fuel feed tube (pump side) (1).
5. Disconnect fuel hose (2) from high pressure fuel pump.
6. Remove high pressure fuel pump and lifter.CAUTION:
After removing lifter, replace lifter with a new one.
7. Disconnect quick connector (A) with the following procedure.
a. Remove quick connector cap from quick connector connection.
b. With the sleeve side of quick connector release facing quick connector, install quick connector release
onto fuel tube.
c. Insert quick connector release into quick connector until sleeve contacts and goes no further. Hold quick connector release on
that position.
CAUTION:
Inserting quick connector re lease hard will not disconnect
quick connector. Hold qui ck connector release where it
contacts and goes no further.
d. Draw and pull out quick connector straight from fuel tube. CAUTION:
 Pull quick connector holding (A) position as shown in thefigure.
 Never pull with lateral force applied. O-ring inside quick
connector may be damaged.
 Prepare container and cloth befo rehand because fuel will leak out.
 Avoid fire and sparks.
 Keep parts away from heat source. Especially, be careful when welding is performed around
them.
 Never expose parts to battery electrolyte or other acids.
 Never bend or twist connection between quick c onnector and fuel feed hose (with damper) dur-
ing installation/removal.
JPBIA3479ZZ
JPBIA3493ZZ
KBIA0702E
Revision: 2010 May2011 QX56

HIGH PRESSURE FUEL PUMP AND FUEL HOSEEM-45
< REMOVAL AND INSTALLATION >
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 To keep clean the connecting portion and to avoid dam-
age and foreign materials, cover them completely with
plastic bags, etc. or a similar item.
8. Disconnect harness connector from low fuel pressure sensor.
9. Remove fuel hose assembly.
10. Remove fuel pressure sensor. CAUTION:
 Never allow water and foreign mate rials enter into the connector.
 Never reuse the dropped sensor.
 Carefully handle sensor avoiding shocks.
 Use hex head support installation fo r removal and installation of sensor.
 The contact surface of gasket must not have any stain or scoring by dust etc.
INSTALLATION
1. Install O-ring to high pressure fuel pump. When handi ng new O-ring, paying attention to the following cau-
tion items:
CAUTION:
 Handle O-ring with bare hands. Never wear gloves.
 Lubricate O-ring with new engine oil.
 Never clean O-ring with solvent.
 Check that O-ring and its mating pa rt are free of foreign material.
 When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretched wh ile it was being attached, never insert it quickly
into fuel tube.
 Insert new O-ring straight into fu el rail. Never decenter or twist it.
2. Install fuel pressure sensor.
3. Install fuel hose assembly.  Temporarily tighten mounting bolt (A) as shown in the figure.
4. Install high pressure fuel pump to front cover. CAUTION:
After removing lifter, replace lifter with a new one.
5. Connect fuel feed hose to high pressure fuel pump. NOTE:
 Never allow the machined edge of the high pr essure fuel pump to contact with gasket.
 The gasket contact area must be free of dust and scratches.
PBIC2205E
: Engine front
JPBIA4250ZZ
Revision: 2010 May2011 QX56