2005 INFINITI QX4 check engine

EC-626Revision: October 2005
IGNITION SIGNAL
2005 QX56
3. CHECK OVERALL FUNCTION
Without CONSULT-II
1. Let engine idle.
2. Read the voltage signal between ECM terminals 46, 60, 61, 62,
65, 79, 80, 81 and ground with an oscilloscope.
3. Verify that the oscilloscope screen shows the signal wave as
shown below.
NOTE:
The pulse cycle changes depending on rpm at idle.
OK or NG
OK >>INSPECTION END
NG >> GO TO 10.
4. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
2. Check voltage between ECM terminals 119, 120 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> Go to EC-157, "
POWER SUPPLY AND GROUND CIR-
CUIT" .
PBIB2094E
PBIB0044E
Voltage: Battery voltage
MBIB0034E

EC-630Revision: October 2005
IGNITION SIGNAL
2005 QX56
7. Remove fuel pump fuse in fuse block No. 1 to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.

It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
17. If NG, replace ignition coil with power transistor.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals 1 and 2.
Removal and InstallationUBS00L1E
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-26, "IGNITION COIL" . Spark should be generated.
BBIA0380E
PBIB2325E
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E

EC-634Revision: October 2005
INJECTOR CIRCUIT
2005 QX56
2. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
Clicking noise should be heard.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
PBIB0133E
PBIB1986E

FUEL PUMP CIRCUIT
EC-639
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EC
Revision: October 20052005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HDE
1. CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check voltage between ECM terminal 113 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
113 GR Fuel pump relay[Ignition switch: ON]

For 1 second after turning ignition switch ON
[Engine is running]0 - 1.5V
[Ignition switch: ON]

More than 1 second after turning ignition
switch ON.BATTERY VOLTAGE
(11 - 14V)
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after ignition switch is turned ON.
BBIA0357E
Voltage: Battery voltage
PBIB11 87 E

REFRIGERANT PRESSURE SENSOR
EC-645
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EC
Revision: October 20052005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HDJ
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
70 B/W Refrigerant pressure sensor[Engine is running]

Warm-up condition

Both A/C switch and blower switch: ON
(Compressor: Operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB11 88 E
BBIA0354E

EI-6
SQUEAK AND RATTLE TROUBLE DIAGNOSES
Revision: October 20052005 QX56
DUPLICATE THE NOISE AND TEST DRIVE
If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on
the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to
duplicate the same conditions when you confirm the repair.
If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to dupli-
cate the noise with the vehicle stopped by doing one or all of the following:
1) Close a door.
2) Tap or push/pull around the area where the noise appears to be coming from.
3) Rev the engine.
4) Use a floor jack to recreate vehicle “twist”.
5) At idle, apply engine load (electrical load, half-clutch on M/T model, drive position on A/T model).
6) Raise the vehicle on a hoist and hit a tire with a rubber hammer.

Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.

If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the
vehicle body.
CHECK RELATED SERVICE BULLETINS
After verifying the customer concern or symptom, check ASIST for Technical Service Bulletins (TSBs) related
to that concern or symptom.
If a TSB relates to the symptom, follow the procedure to repair the noise.
LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE
1. Narrow down the noise to a general area.To help pinpoint the source of the noise, use a listening tool
(Chassis Ear: J-39570, Engine Ear: J-39565 and mechanic's stethoscope).
2. Narrow down the noise to a more specific area and identify the cause of the noise by:

removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners can be bro-
ken or lost during the repair, resulting in the creation of new noise.

tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only
temporarily.

feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing the
noise.

placing a piece of paper between components that you suspect are causing the noise.

looking for loose components and contact marks.
Refer to EI-7, "
Generic Squeak and Rattle Troubleshooting" .
REPAIR THE CAUSE

If the cause is a loose component, tighten the component securely.

If the cause is insufficient clearance between components:
–separate components by repositioning or loosening and retightening the component, if possible.
–insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or ure-
thane tape. A NISSAN Squeak and Rattle Kit (J-43980) is available through your authorized NISSAN
Parts Department.
CAUTION:
Do not use excessive force as many components are constructed of plastic and may be damaged.
Always check with the Parts Department for the latest parts information.
The following materials are contained in the NISSAN Squeak and Rattle Kit (J-43980). Each item can be
ordered separately as needed.
URETHANE PADS [1.5 mm (0.059 in) thick]
Insulates connectors, harness, etc.
76268-9E005: 100×135 mm (3.94×5.31 in)/76884-71L01: 60×85 mm (2.36×3.35 in)/76884-71L02: 15×25
mm (0.59×0.98 in)
INSULATOR (Foam blocks)
Insulates components from contact. Can be used to fill space behind a panel.
73982-9E000: 45 mm (1.77 in) thick, 50×50 mm (1.97×1.97 in)/73982-50Y00: 10 mm (0.39 in) thick,
50×50 mm (1.97×1.97 in)
INSULATOR (Light foam block)

EM-1
ENGINE MECHANICAL
B ENGINE
CONTENTS
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SECTION EM
A
EM
Revision: October 20052005 QX56 PRECAUTIONS .......................................................... 3
Precautions for Drain Engine Coolant ...................... 3
Precautions for Disconnecting Fuel Piping .............. 3
Precautions for Removal and Disassembly ............. 3
Precautions for Inspection, Repair and Replace-
ment ......................................................................... 3
Precautions for Assembly and Installation ............... 3
Parts Requiring Angular Tightening ......................... 3
Precautions for Liquid Gasket .................................. 4
REMOVAL OF LIQUID GASKET SEALING .......... 4
LIQUID GASKET APPLICATION PROCEDURE ..... 4
PREPARATION ........................................................... 5
Special Service Tools ............................................... 5
Commercial Service Tools ........................................ 7
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 9
NVH Troubleshooting —Engine Noise ..................... 9
Use the Chart Below to Help You Find the Cause
of the Symptom. ..................................................... 10
ENGINE ROOM COVER ...........................................11
Removal and Installation .........................................11
REMOVAL ............................................................11
INSTALLATION ....................................................11
DRIVE BELTS ........................................................... 12
Checking Drive Belts .............................................. 12
Tension Adjustment ................................................ 12
Removal and Installation ........................................ 12
DRIVE BELT ....................................................... 12
INSTALLATION ................................................... 13
Drive Belt Auto Tensioner and Idler Pulley ............. 13
REMOVAL ........................................................... 13
INSTALLATION ................................................... 13
AIR CLEANER AND AIR DUCT ............................... 14
Removal and Installation ........................................ 14
REMOVAL ........................................................... 14
INSTALLATION ................................................... 14
CHANGING AIR CLEANER FILTER ................... 14INTAKE MANIFOLD ................................................. 15
Removal and Installation ........................................ 15
REMOVAL ........................................................... 15
INSTALLATION ................................................... 17
INSPECTION AFTER INSTALLATION ................ 18
EXHAUST MANIFOLD AND THREE WAY CATA-
LYST .......................................................................... 19
Removal and Installation ........................................ 19
REMOVAL ........................................................... 19
INSPECTION AFTER REMOVAL ....................... 20
INSTALLATION ................................................... 20
OIL PAN AND OIL STRAINER ................................. 22
Removal and Installation ........................................ 22
REMOVAL ........................................................... 22
INSPECTION AFTER REMOVAL ....................... 23
INSTALLATION ................................................... 24
INSPECTION AFTER INSTALLATION ................ 25
IGNITION COIL ......................................................... 26
Removal and Installation ........................................ 26
REMOVAL ........................................................... 26
INSTALLATION ................................................... 26
SPARK PLUG (PLATINUM-TIPPED TYPE) ............. 27
Removal and Installation ........................................ 27
REMOVAL ........................................................... 27
INSPECTION AFTER REMOVAL ....................... 27
INSTALLATION ................................................... 28
FUEL INJECTOR AND FUEL TUBE ........................ 29
Removal and Installation ........................................ 29
REMOVAL ........................................................... 29
INSTALLATION ................................................... 30
INSPECTION AFTER INSTALLATION ................ 32
ROCKER COVER ..................................................... 33
Removal and Installation ........................................ 33
REMOVAL ........................................................... 33
INSTALLATION ................................................... 34
TIMING CHAIN .......................................................... 35
Removal and Installation ........................................ 35
REMOVAL ........................................................... 36
INSPECTION AFTER REMOVAL ....................... 38
INSTALLATION ................................................... 39

EM-2Revision: October 20052005 QX56 CAMSHAFT ............................................................... 43
Removal and Installation ........................................ 43
REMOVAL ........................................................... 43
INSPECTION AFTER REMOVAL ........................ 46
INSTALLATION .................................................... 48
Valve Clearance ...................................................... 51
INSPECTION ....................................................... 51
ADJUSTMENT .................................................... 53
OIL SEAL .................................................................. 55
Removal and Installation of Valve Oil Seal ............. 55
REMOVAL ........................................................... 55
INSTALLATION .................................................... 55
Removal and Installation of Front Oil Seal ............. 56
REMOVAL ........................................................... 56
INSTALLATION .................................................... 56
Removal and Installation of Rear Oil Seal .............. 56
REMOVAL ........................................................... 56
INSTALLATION .................................................... 57
CYLINDER HEAD ..................................................... 58
On-Vehicle Service ................................................. 58
CHECKING COMPRESSION PRESSURE ......... 58
Removal and Installation ........................................ 59
REMOVAL ........................................................... 59
INSPECTION AFTER REMOVAL ........................ 60
INSTALLATION .................................................... 60
Disassembly and Assembly .................................... 61
DISASSEMBLY ................................................... 61
ASSEMBLY ......................................................... 62
Inspection After Disassembly ................................. 63
CYLINDER HEAD DISTORTION ........................ 63
VALVE DIMENSIONS .......................................... 64
VALVE GUIDE CLEARANCE .............................. 65
VALVE GUIDE REPLACEMENT ......................... 65
VALVE SEAT CONTACT ..................................... 67
VALVE SEAT REPLACEMENT ........................... 67
VALVE SPRING SQUARENESS ......................... 68
VALVE SPRING DIMENSIONS AND VALVE
SPRING PRESSURE LOAD ............................... 68
ENGINE ASSEMBLY ................................................ 69
Removal and Installation ........................................ 69
REMOVAL ........................................................... 69
INSTALLATION .................................................... 72
INSPECTION AFTER INSTALLATION ................ 72
CYLINDER BLOCK ................................................... 73
Disassembly and Assembly .................................... 73
DISASSEMBLY ................................................... 74ASSEMBLY ..........................................................77
How to Select Piston and Bearing ..........................82
DESCRIPTION ....................................................82
HOW TO SELECT PISTON .................................83
HOW TO SELECT CONNECTING ROD BEAR-
ING .......................................................................84
HOW TO SELECT MAIN BEARING ....................85
Inspection After Disassembly ..................................89
CRANKSHAFT END PLAY ..................................89
CONNECTING ROD SIDE CLEARANCE ...........89
PISTON AND PISTON PIN CLEARANCE ...........89
PISTON RING SIDE CLEARANCE .....................90
PISTON RING END GAP ....................................90
CONNECTING ROD BEND AND TORSION .......91
CONNECTING ROD BEARING (BIG END) ........91
CONNECTING ROD BUSHING OIL CLEAR-
ANCE (SMALL END) ...........................................91
CYLINDER BLOCK DISTORTION ......................92
MAIN BEARING HOUSING INSIDE DIAMETER ...93
PISTON TO CYLINDER BORE CLEARANCE ....93
CRANKSHAFT JOURNAL DIAMETER ...............94
CRANKSHAFT PIN DIAMETER ..........................95
OUT-OF-ROUND AND TAPER OF CRANK-
SHAFT .................................................................95
CRANKSHAFT RUNOUT ....................................95
CONNECTING ROD BEARING OIL CLEAR-
ANCE ...................................................................95
MAIN BEARING OIL CLEARANCE .....................96
CRUSH HEIGHT OF MAIN BEARING ................97
CRUSH HEIGHT OF CONNECTING ROD
BEARING .............................................................97
MAIN BEARING CAP BOLT DIAMETER .............97
CONNECTING ROD BOLT DIAMETER ..............98
SERVICE DATA AND SPECIFICATIONS (SDS) ......99
Standard and Limit ..................................................99
GENERAL SPECIFICATIONS .............................99
DRIVE BELTS ......................................................99
EXHAUST MANIFOLD ........................................99
CAMSHAFT AND CAMSHAFT BEARING ......... 100
CYLINDER HEAD .............................................. 102
CYLINDER BLOCK ............................................ 104
PISTON, PISTON RING AND PISTON PIN ...... 105
CONNECTING ROD .......................................... 105
CRANKSHAFT ................................................... 106
MAIN BEARING ................................................. 107