EC-484
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-33
,
LU-
14 , LU-11 ,
LU-12
Oil level (Low)/Filthy oil LU-8, "In-
spection"
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-15
Thermostat
5CO-22
Water pump CO-20
Water galleryCO-6
Cooling fan5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-8
SYMPTOM
Reference
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
EC-488
< PRECAUTION >[VK56DE]
PRECAUTIONS
•
When connecting ECM harness co nnector, fasten it securely
with a lever as far as it will go as shown in the figure.
• When connecting or disconnect ing pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM pin
terminal, when connecting pin connectors.
• Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge) volt-
age to develop in coil and co ndenser, thus resulting in dam-
age to ICs.
• Keep engine control system harness at least 10 cm (4 in) away
from adjacent harness, to preven t engine control system mal-
functions due to receiving external noise, degraded operation
of ICs, etc.
• Keep engine control system parts and harness dry.
• Before replacing ECM, perform ECM Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-429, "
ECM Terminal and Reference Value".
• Handle mass air flow sensor carefully to avoid damage.
• Do not disassemble m ass air flow sensor.
• Do not clean mass air flow sensor with any type of detergent.
• Do not disassemble electric throttle control actuator.
• Even a slight leak in the ai r intake system can cause serious
incidents.
• Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
• After performing each TROUBLE DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displ ayed in the DTC Confirmation
Procedure if the repair is co mpleted. The Overall Function
Check should be a good result if the repair is completed.
BBIA0387E
PBIB0090E
MEF040D
SEF217U
Revision: March 2010 2008 QX56
EC-500
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL
Intake Valve Timing Control Solenoid Valve (LH)INFOID:0000000001830643
REMOVAL
1. Remove engine room cover using power tool. Refer to
EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-24, "
Removal and Installation".
3. Remove drive belt. Refer to EM-13, "
Removal and Installation".
4. Disconnect Intake valve timing controlintake valve timing control solenoid valve connector (LH).
5. Remove Intake valve timing control solenoid valve (LH) (2) from Intake valve timing control solenoid valve cover (LH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (3) of the Intake valve timing co ntrol solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
Intake Valve Timing Control Solenoid Valve (RH)INFOID:0000000001830644
REMOVAL
1. Remove drive belt. Refer to EM-13, "Removal and Installation".
2. Disconnect Intake valve timing control solenoid valve connector (RH).
3. Remove Intake valve timing control solenoid valve (RH) (3) from Intake valve timing control solenoid valve cover (RH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the Intake valve timing co ntrol solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
AWBIA0145ZZ
Intake valve timing control sole-
noid valve bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
AWBIA0144ZZ
Intake valve timing control sole-
noid valve bolt: 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: March 2010
2008 QX56
INTAKE VALVE TIMING CONTROLEC-501
< ON-VEHICLE REPAIR > [VK56DE]
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Intake Valve Timing Control Position Sensor (LH)INFOID:0000000001830645
REMOVAL
1. Remove engine room cover using power tool. Refer to
EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-25, "
Removal and Installation".
3. Disconnect intake valve timing control position sensor connector (LH).
4. Remove intake valve timing control position sensor (LH) (1) from Intake valve timing control solenoid valve cover (LH) (3).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the intake valve timing control position sensor with a new one, then lubricate
O-ring with engine oil before installing.
Intake Valve Timing Cont rol Position Sensor (RH)INFOID:0000000001830646
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Disconnect intake valve timing control position sensor connector (RH).
3. Remove intake valve timing control position sensor (RH) (1) from Intake valve timing control solenoid valve cover (RH) (3).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the intake valve timing control position sensor with a new one, then lubricate
O-ring with engine oil before installing.
Camshaft Position Sensor (PHASE)INFOID:0000000001830647
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-25, "
Removal and Installation".
3. Disconnect camshaft position sensor connector.
AWBIA0141ZZ
Intake valve timing control position sensor bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
AWBIA0143ZZ
Intake valve timing control position sensor bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: March 2010 2008 QX56
EC-502
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
4. Remove camshaft position sensor (2) from Intake valve timing
control solenoid valve cover (LH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (3) of the cam shaft position sensor with a new on e, then lubricate O-ring with
engine oil before installing.
AWBIA0142ZZ
Camshaft position sensor bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: March 2010 2008 QX56
EM-1
ENGINE
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SECTION EM
A
EM
N
O P
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-2
Inspection after Installation .....................................62
OIL SEAL ........................................................ ...64
Removal and Installation of Valve Oil Seal .......... ...64
Removal and Installation of Front Oil Seal .............64
Removal and Installation of Rear Oil Seal ..............66
CYLINDER HEAD ..............................................68
Exploded View ..................................................... ...68
Removal and Installation ........................................68
Disassembly and Assembly ....................................70
Inspection After Disassembly .................................72
REMOVAL AND INSTAL LATION ...............78
ENGINE ASSEMBLY ...................................... ...78
Removal and Installation ..................................... ...78
DISASSEMBLY AND ASSEMBLY ............82
ENGINE UNIT ....................................................82
Disassembly and Assembly ................................. ...82
Inspection After Disassembly ..................................90
HOW TO SELECT PISTON AND BEARING ...101
How to Select Piston and Bearing ....................... .101
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
108
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
108
Standard and Limit ............................................... .108
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