2009 INFINITI QX56 engine

COMPRESSION PRESSUREEM-23
< ON-VEHICLE MAINTENANCE >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
COMPRESSION PRESSURE
Checking Compression PressureINFOID:0000000005885870
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-487, "
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-8, "
Trouble Diagnosis Introduction".
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: December 20092009 QX56

EM-24
< ON-VEHICLE REPAIR >
ENGINE ROOM COVER
ON-VEHICLE REPAIR
ENGINE ROOM COVER
Removal and InstallationINFOID:0000000005885871
CAUTION:
Do not damage or scratch engine room cover when installing or removing.
REMOVAL
• Remove the engine room cover bolts and engine room cover.
INSTALLATION
Installation is in the reverse order of removal.
WBIA0795E
Revision: December 20092009 QX56

AIR CLEANER AND AIR DUCTEM-25
< ON-VEHICLE REPAIR >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
AIR CLEANER AND AIR DUCT
Exploded ViewINFOID:0000000005885872
Removal and InstallationINFOID:0000000005885873
REMOVAL
1. Remove the engine room cover using power tool. Refer to
EM-24, "Removal and Installation".
2. Disconnect the harness connector from air cleaner case (upper).
3. Disconnect crankcase ventil ation hoses at resonator.
4. Remove the air duct and resonator assembly and air cleaner case.
5. Remove air cleaner filter and air cleaner case (lower)
• Add marks as necessary for easier installation.
INSTALLATION
Installation is in the reverse order of removal.
1. Air cleaner case (lower) 2. Air cleaner filter 3. Air cleaner case (upper)
4. Air duct and resonator assembly Front
ALBIA0413GB
Revision: December 20092009 QX56

EM-26
< ON-VEHICLE REPAIR >
INTAKE MANIFOLD
INTAKE MANIFOLD
Exploded ViewINFOID:0000000005885874
Removal and InstallationINFOID:0000000005885875
REMOVAL
1. Partially drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
WARNING:
To avoid the danger of being scal ded, never drain the engine coolant when the engine is hot.
2. Release the fuel pressure. Refer to EC-487, "
Fuel Pressure Check".
3. Disconnect the negative battery terminal. Refer to PG-76, "
Removal and Installation".
4. Remove the air duct and resonator assembly. Refer to EM-25, "
Removal and Installation".
5. Disconnect the fuel tube quick connector on the engine side in the following steps.
1. Intake manifold 2. PCV hose 3. Gasket
4. Electric throttle control actuator 5. Water hose 6. Water hose
7. PCV hose 8. EVAP hose 9. EVAP canister purge control solenoid
valve
10. Bracket 11. Gasket
KBIA2461E
LBIA0395E
Revision: December 20092009 QX56

INTAKE MANIFOLDEM-27
< ON-VEHICLE REPAIR >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
a. Remove quick connector cap (engine side only).
b. With the sleeve side of Tool facing quick connector, install Tool
onto fuel tube.
c. Insert Tool into quick connector until sleeve contacts and goes no further. Hold the Tool in that position.
CAUTION:
Inserting the Tool hard will not disconnect quick connector.
Hold Tool where it cont acts and goes no further.
d. Draw and pull out quick connector straight from fuel tube. CAUTION:
• Pull quick connector holding "A" position in illustration.
• Do not pull with lateral force applied. O-ring inside quick connector may be damaged.
• Prepare container and cloth be forehand as fuel will leak out.
• Avoid fire and sparks.
• Be sure to cover openings of disconnected pipes with plug or plastic bag to avoid fuel leakage and entry of foreign materials.
6. Remove or disconnect harnesses, brake booster va cuum hose and PCV hose and tube from intake man-
ifold.
7. Remove the EVAP canister purge control solenoid valve and bracket, if necessary.
8. Remove electric throttle control actuator by loosening bolts diagonally. CAUTION:
• Handle carefully to avoid any damage to the electric throttle control actuator.
• Do not disassemble.
9. Remove the fuel injectors and fuel tube assembly. Refer to EM-40, "
Removal and Installation".
10. Loosen the bolts in reverse order shown using power tool.
11. Remove the intake manifold. CAUTION:
Cover engine openings to avoid entry of foreign materials.
• Clean all gasket mating surfaces, do not reuse gaskets.
INSTALLATION
Installation is in the reverse order of removal.
SBIA0354E
Tool number : 16441 6N210 (J-45488)
WBIA0604E
KBIA2462E
Revision: December 20092009 QX56

EM-28
< ON-VEHICLE REPAIR >
INTAKE MANIFOLD
• Tighten the intake manifold bolts in numerical order as shown.
• Install the EVAP canister purge control solenoid valve connector with it facing front of engine.
• Tighten the electronic throttle control actuator bolts of the electric throttle control actuator equally and diago-
nally in several steps.
• After installation perform procedure in "INSPECTION AFTER INSTALLATION".
• Install the water hose so that its overlap width for connection is between 27 mm (1.06 in) and 32 mm (1.26 in) (target: 27 mm 1.06 in).
Connecting Quick Connector of Fuel Tube
Install quick connector as follows (the steps are t he same for quick connectors on both engine side and vehi-
cle side except for the quick connector cap).
1. Make sure no foreign substances are deposited in and around tube and quick connector, and they are not damaged.
2. Thinly apply new engine oil around the fuel tube from tip end to the spool end.
3. Align center to insert quick connector straight into fuel tube. • Insert until the paint mark for engagement identification (white)goes completely inside quick connector so that you cannot see
it from the straight side of the connected part. Use a mirror to
check this where it is not possible to view directly from the
straight side, such as quick connector on vehicle side.
• Insert fuel tube into quick connector until top spool is com- pletely inside quick connector, and 2nd level spool exposes
right below quick connector on engine side.
CAUTION:
• Hold "A" position in illustration when inserting fuel tubeinto quick connector.
• Carefully align center to avoid inclined insertion to pre-
vent damage to O-ring inside quick connector.
• Insert until you hear a "click" sound and actually feel the
engagement.
• To avoid misidentification of engagement with a similar
sound, be sure to pe rform the next step.
4. Pull quick connector by hand holding "A" position. Make sure it is completely engaged (connected) so that
it does not come out from fuel tube.
NOTE:
Recommended pulling force is 50 N (5.1 kg, 11.2 lb).
KBIA2462E
PBIC0017E
KBIA0272E
Revision: December 20092009 QX56

INTAKE MANIFOLDEM-29
< ON-VEHICLE REPAIR >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
5. Install the quick connector cap on the quick connector joint (on
engine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to CO-11, "
Changing Engine
Coolant".
INSPECTION AFTER INSTALLATION
• After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.
- Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at connections.
- Start the engine and rev it up and check for fuel leaks at the connections.
• Perform procedures for “Throttle Valve Closed Position Learning” after finishing repairs. Refer to EC-18,
"Throttle Valve Closed Position Learning".
• If electric throttle control actuator is replaced, per form procedures for “Idle Air Volume Learning” after finish-
ing repairs. Refer to EC-18, "
Idle Air Volume Learning".
SBIA0354E
Revision: December 20092009 QX56

EM-30
< ON-VEHICLE REPAIR >
EXHAUST MANIFOLD AND THREE WAY CATALYST
EXHAUST MANIFOLD AND THREE WAY CATALYST
Exploded ViewINFOID:0000000005885876
Removal and InstallationINFOID:0000000005885877
REMOVAL
WARNING:
Perform the work when the exhaust and cooling system have cooled sufficiently.
1. Remove the engine undercover (rear) using power tool (4WD models).
2. Remove front final drive assembly (4WD models). Refer to DLN-215, "
Removal and Installation".
3. Remove the main muffler assembly and center exhaust tube. Refer to EX-6, "
Removal and Installation".
4. Remove the front exhaust tubes. Refer to EX-6, "
Removal and Installation".
5. Remove front tires. Refer to WT-41, "
Adjustment".
6. Remove fender protectors. Refer to EXT-23, "
Removal and Installation".
7. Remove the LH and RH air fuel ratio A/F sensors. • Follow steps below to remove each air fuel ratio A/F sensor.
a. Remove the harness connector of each air fuel ra tio A/F sensor, and harness from bracket and middle
clamp.
1. Air fuel ratio A/F sensor 1 (bank 2) 2. Exhaust manifold cover (bank 2) 3. Exhaust manifold (bank 2)
4. Gaskets 5. Exhaust manifold (bank 1) 6. Exhaust manifold cover (bank 1)
7. Air fuel ratio A/F sensor 1 (bank 1) A. Up B. Coated face
C. Manifold side D. Up mark Front
AWBIA0453GB
Revision: December 20092009 QX56