2008 INFINITI QX56 oil pressure

EC-482
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-106,
EC-113
Engine coolant temperature sensor circuit
333
EC-124,
EC-132
Air fuel ratio (A/F ) sensor 1 circuit EC-141
,
EC-145
,
EC-149
,
EC-153
,
EC-385
Throttle position sensor circuit
22EC-128
,
EC-194
,
EC-310
,
EC-312
,
EC-377
Accelerator pedal position sensor circuit 3 2 1EC-289
,
EC-370
,
EC-373
,
EC-381
Knock sensor circuit 23EC-204
Crankshaft position sensor (POS) circuit 2 2 EC-207
Camshaft position sensor (PHASE) circuit 3 2 EC-211
Vehicle speed signal circuit2 3 33EC-280
Power steering pressu re sensor circuit 23 3 EC-286
ECM 22333333333 EC-289,
EC-291
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-103
Park/Neutral position (PNP) signal circuit3 3 3 33EC-296
Refrigerant pressure sensor circuit 233 4 EC-423
Electrical load signal circuit 3EC-397
Air conditioner circuit 223333333 3 2 HAC-24
ABS actuator and electric unit (control unit) 4 BRC-37
SYMPTOM
Refer-
ence 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: March 2010 2008 QX56

EM-1
ENGINE
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SECTION EM
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EM
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CONTENTS
ENGINE MECHANICAL
PRECAUTION ....... ........................................3
PRECAUTIONS .............................................. .....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 .........................4
Precaution for Disconnecting Fuel Piping .................4
Precaution for Removal and Disassembly ................4
Precaution for Inspection, Repair and Replace-
ment .................................................................... ......
4
Precaution for Assembly and Installation ..................4
Parts Requiring Angular Tightening ..........................4
Precaution for Liquid Gasket ............................... ......5
PREPARATION ............................................6
PREPARATION .............................................. .....6
Special Service Tool ........................................... ......6
Commercial Service Tool ..........................................8
FUNCTION DIAGNOSIS ..............................10
NOISE, VIBRATION, AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ ....
10
NVH Troubleshooting - Engine Noise ................. ....10
Use the Chart Below to Help You Find the Cause
of the Symptom .......................................................
11
ON-VEHICLE MAINTENANCE ....................13
DRIVE BELTS ................................................ ....13
Checking Drive Belts ........................................... ....13
Removal and Installation .........................................13
Drive Belt Auto Tensioner and Idler Pulley ......... ....14
AIR CLEANER FILTER ......................................15
Removal and Installation (Viscous paper type) ... ....15
SPARK PLUG ................................................ ....16
Removal and Installation ..................................... ....16
CAMSHAFT VALVE CLEARANCE ..................18
Valve Clearance ......................................................18
COMPRESSION PRESSURE ...........................23
Checking Compression Pressure ............................23
ON-VEHICLE REPAIR .................................24
ENGINE ROOM COVER ...................................24
Removal and Installation ..................................... ....24
AIR CLEANER AND AIR DUCT .......................25
Removal and Installation .........................................25
INTAKE MANIFOLD .........................................26
Removal and Installation .........................................26
EXHAUST MANIFOLD AND THREE WAY
CATALYST ........................................................
30
Exploded View .........................................................30
Removal and Installation .........................................30
OIL PAN AND OIL STRAINER .........................33
Removal and Installation .........................................33
IGNITION COIL .................................................37
Removal and Installation .........................................37
ROCKER COVER .............................................38
Removal and Installation .........................................38
FUEL INJECTOR AND FUEL TUBE ................40
Removal and Installation .........................................40
TIMING CHAIN ..................................................44
Components ........................................................ ....44
Removal and Installation .........................................45
CAMSHAFT .......................................................53
Components ............................................................53
Removal and Installation .........................................53
Revision: March 2010 2008 QX56

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-6
< PREPARATION >
PREPARATION
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000001538801
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool name Description
K V 1 0 1111 0 0
(J-37228)
Seal cutter Removing steel oil pan and rear timing chain
case
—
(J-44626)
Air fuel sensor Socket Loosening or tightening air fuel ratio A/F sen-
sor
a: 22 mm (0.87 in)
EG15050500
(J-45402)
Compression gauge adapter Inspecting compression pressure
KV10116200
(J-26336-A)
Valve spring compressor
1. KV10115900
(J-26336-20)
Attachment
2. KV10109220
(—)
Adapter Disassembling valve mechanism
Part (1) is a component of KV10116200 (J-
26336-A), but part (2) is not.
KV10112100
(BT-8653-A)
Angle wrench Tightening bolts for cylinder head, main bear-
ing cap and connecting rod cap
KV10107902
(J-38959)
Valve oil seal puller Removing valve oil seal
S-NT046
LBIA0444E
ZZA1225D
PBIC1650E
S-NT014
S-NT011
Revision: March 2010
2008 QX56

EM-16
< ON-VEHICLE MAINTENANCE >
SPARK PLUG
SPARK PLUG
Removal and InstallationINFOID:0000000001538809
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Remove ignition coil. Refer to EM-37, "
Removal and Installation".
3. Remove spark plug using suitable tool.
INSPECTION AFTER REMOVAL
• Do not use a wire brush for cleaning.
• If plug tip is covered with carbon, spark plug cleaner may be used.
1. Ignition coil 2. Spark plug
WBIA0796E
SEM294A
Cleaner air pressure:
Less than 588 kPa (5.9 bar, 6 kg/cm
2 , 85 psi)
Cleaning time: Less than 20 seconds
SMA773C
Revision: March 2010 2008 QX56

COMPRESSION PRESSUREEM-23
< ON-VEHICLE MAINTENANCE >
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COMPRESSION PRESSURE
Checking Compression PressureINFOID:0000000001538811
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
CAUTION:
If CONSULT-III is not used to release fuel pressure leave the fuel pump fuse disconnected until
step 7.
3. Remove the spark plug from each cylinder. Refer to EM-16, "
Removal and Installation".
4. Connect the engine tachometer (not required in use of CONSULT-III).
5. Install the compression tester with Tool into the spark plug hole.
6. With the accelerator pedal fully depressed, turn the ignition switch to “START” for cranking. When the gauge pointer stabi-
lizes, read the compression pressure and engine rpm. Perform
these steps to check each cylinder.
Unit: kPa (kg/cm2, psi) /rpm
CAUTION:
Always use a fully charged battery to obtain specified engine speed.
• If the engine speed is out of the specified range, check the battery liquid for proper gravity. Check the engine speed again with normal battery gravity.
• If the compression pressure is below the minimum value, check the valve clearances and parts associ-
ated with the combustion chamber (valve, valve seat , piston, piston ring, cylinder bore, cylinder head,
cylinder head gasket). After checking, measure the compression pressure again.
• If some cylinders have 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, t he piston rings may be worn out or damaged. Check
the piston rings and replace if necessary.
- If the compression pressure remains at a low level despite the addition of engine oil, the valves may be malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly.
• If two adjacent cylinders have respectively low compression pressure and their compression remains low even after the addition of engine oil, the gaskets may be leaking, or a valve in adjacent cylinders
may be damaged. Inspect and repair as required.
7. Install the components in the reverse order of removal.
8. Start the engine and confirm that it runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-75, "
Description".
Tool number : EG15050500 (J-45402)
Standard
MinimumDeference limit be-
tween cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200WBIA0605E
Revision: March 2010 2008 QX56

OIL PAN AND OIL STRAINEREM-33
< ON-VEHICLE REPAIR >
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OIL PAN AND OIL STRAINER
Removal and InstallationINFOID:0000000001538816
REMOVAL
WARNING:
To avoid the danger of being scalded, never drain the engine oil when the engine is hot.
1. Remove the engine. Refer to
EM-78, "
Removal and Installation".
2. Remove the oil pan (lower) using the following steps.
a. Remove the oil pan (lower) bolts using power tool.
1. Oil pan (upper) 2. O-ring3. O-ring
4. O-ring 5. O-ring (with collar)6. Oil level gauge guide
7. Oil level gauge 8. O-ring9. Connector bolt
10. Oil filter 11. Oil cooler12. Relief valve
13. Oil pressure switch 14. Gasket15. Drain plug
16. Oil pan (lower) 17. Oil strainer
KBIA2465E
KBIA2466E
Revision: March 2010 2008 QX56

FUEL INJECTOR AND FUEL TUBEEM-41
< ON-VEHICLE REPAIR >
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7. Remove fuel injector from fuel tube.
a. Spread open to remove clip.
b. Remove fuel injector from the
fuel tube by pulling straight out.
CAUTION:
• Be careful with remaining fuel that may leak out from fuel
tube.
• Do not damage injector nozzles during removal.
• Do not bump or drop fuel injectors.
• Do not disassemble fuel injectors.
8. Remove fuel damper from each fuel tube.
INSTALLATION
1. Install fuel damper to each fuel tube.
a. Apply engine oil to O-ring and set it into the cap of fuel tube. CAUTION:
• Handle O-ring with bare hands. Never wear gloves.
• Lubricate O-ring with new engine oil.
• Do not clean O-ring with solvent.
• Make sure that O-ring and its mating part are free of for- eign material.
• When installing O-ring, be car eful not to scratch it with
tool or fingernails. Also be careful not to twist or stretch
O-ring.
b. Make sure that backup spacer is in the O-ring connecting sur- face of fuel damper.
NOTE:
Backup spacer is fuel damper assembly part.
c. Insert fuel damper until it seats on fuel tube. CAUTION:
• Insert straight, making sure that the axis is lined up.
• Do not pressure-fit with excessive force.
d. Install cap, and then tighten bolts evenly by turns. • After tightening bolts, make sure that there is no gap between cap and fuel tube.
2. Install O-rings to fuel injector paying attention to the items below. CAUTION:
• Upper and lower O-ring are different.
• Handle O-ring with bare hands. Never wear gloves.
KBIA2506E
Reference value :130 N (13.3 kg, 29.2 lb)
Fuel tube side : Blue
Nozzle side : Brown
KBIA2473E
Revision: March 2010 2008 QX56