2011 INFINITI QX56 check engine

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 >
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 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.
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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
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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)
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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
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ZZA1210D
Revision: 2010 May2011 QX56

CAMSHAFT VALVE CLEARANCEEM-13
< BASIC INSPECTION >
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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:
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1 : Exhaust camshaft (bank 1) : Engine front
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: 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)
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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.
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Compression pressure : Refer to EM-132, "GeneralSpecification".
Revision: 2010 May2011 QX56

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGEM-19
< SYMPTOM DIAGNOSIS >
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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

EM-20
< PERIODIC MAINTENANCE >
DRIVE BELTS
PERIODIC MAINTENANCE
DRIVE BELTS
Exploded ViewINFOID:0000000006289524
CheckingINFOID:0000000006289525
WARNING:
Be sure to perform the these steps when engine is stopped.
 Check that the indicator (C) (notch on fixed side) of each auto-tensioner is within the possible use range (A).
NOTE:
 Check the each auto-tensioners indication when the engine is cold.
 When new drive belts is installed, the indicator (notch on fixed side) should be within the range (B) in the\
figure.
 Visually check all drive belts for wear, damage or cracks.
 If the indicator (notch on fixed side) is out of the possible use range or drive belts are damaged, replace drive
belts.
Tension AdjustmentINFOID:0000000006289526
Refer to EM-132, "Drive Belts".
Removal and InstallationINFOID:0000000006289527
REMOVAL
1. Move reservoir tank to the position without the hindrance for work. Refer to CO-13, "Exploded View".
1. Drive belt 2. Power steering oil pump pulley 3. Alternator pulley
4. Crankshaft pulley 5. A/C compressor 6. Idler pulley
7. Cooling fan pulley 8. Water pump pulley 9. Drive belt auto-tensioner
A. Possible use range B. Range when new drive belt is in-
stalledC. Indicator
D. View D
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