2007 INFINITI QX56 check engine

EM-64
< SERVICE INFORMATION >
CYLINDER HEAD
CYLINDER HEAD
On-Vehicle ServiceINFOID:0000000003531540
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-80, "
Fuel Pressure Check".
CAUTION:
If CONSULT-II is not used to release fuel pressure leave the fu el pump fuse disconnected until
step 7.
3. Remove the spark plug from each cylinder. Refer to EM-29, "
Removal and Installation".
4. Connect the engine tachometer (not required in use of CONSULT-II).
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, che ck 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. R eplace the valve or valve seat accordingly.
• If two adjacent cylinders have respectively low co mpression 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-32
.
Tool number : EG15050500 (J-45402)
Standard Minimum
Deference limit be-
tween cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200WBIA0605E

EM-66
< SERVICE INFORMATION >
CYLINDER HEAD
•Cylinder head bolts are tight ened by pla stic zone tight ening
method.
Whenever the size diff erence between d1 and d2 exceeds
t he limit, r eplace the bolt with a new one.
•If reduction of diameter appears in a position other than d2, use it
as
d2 point.
I NST ALLA TION
1.Install a new cylinder head ga sket.
2. Install the cylinder head. Follow the steps below to tighten the
bol
ts in the numerical order shown.
CAUTIO
N:
•If cy lind er head bolts are re -u se d, check their diameters
before
inst allation. Refer to GI-45, "Reco mme nded Chemi-
cal Product and Sealant".
a. Apply engine oil to threads and seating surface of the bolts.
b. Measure the tightening angle using T ool.
CAUTIO
N:
M easure the tighte ning angle using Tool. Do not measure
visuall
y.
3.I nstallation of t he remaining components is in t he reverse order of removal.
Limit

(d1 - d2): 0.18 mm (0.0071 in)
KBIA 0189E
Step a: 44.1 N·m (4.5 kg -m, 33 f t- lb )
Step c :Loosen in the reverse order of tightening.
Step d : 44.1 N·m (4.5 kg-m, 33 ft-lb)
PBIC0068E
Tool number: KV101 12100 (BT-8653-A)
St ep e : 60° clockwise
Step b : 70° clockwise
Step f : 60° clockwise
WBIA 0603E

EM-74
< SERVICE INFORMATION >
ENGINE ASSEMBLY
ENGINE ASSEMBLY
Removal and InstallationINFOID:0000000003531544
WARNING:
• Situate vehicle on a flat and solid surface.
• Place chocks at front and back of rear wheels.
• For engines not equipped with engine slingers, attach proper slingers and bolts described in PARTS
CATALOG.
CAUTION:
• Always be careful to work safely, avoid forceful or uninstructed operations.
• Do not start working until exhaust system and engine coolant are cooled sufficiently.
• If items or work required are not covered by the engine section, refer to the applicable sections.
• Always use the support point specified for lifting.
• Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,
support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.
• For supporting points for lifting and jacking point at rear axle, refer to GI-40, "
Garage Jack and
Safety Stand".
REMOVAL
Preparation
1. Drain the engine coolant. Refer to CO-9, "Changing Engine Coolant".
2. Partially drain the A/T fluid. Refer to AT-13, "
Changing Automatic Transmission Fluid (ATF)".
3. Release the fuel pressure. Refer to EC-80, "
Fuel Pressure Check".
4. Remove the engine hood. Refer to BL-12, "
Removal and Installation of Hood Assembly".
5. Remove the cowl extension. Refer to EI-17, "
Removal and Installation".
1. Rear engine mounting insulator 4WD 2. Rear engine mounting insulator 2WD 3. LH engine mounting bracket
4. LH heat shield plate 5. LH engine mounting insulator 6. RH engine mounting bracket
7. RH heat shield plate 8. RH engine mounting insulator
LBIA0397E

ENGINE ASSEMBLY
EM-75
< SERVICE INFORMATION >
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6. Remove the engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly. Refer to EM-15, "
Removal and Installation".
8. Disconnect the vacuum hose between the vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-13, "
Removal and Installation".
10. Remove the drive belts. Refer to EM-15, "
Removal and Installation".
11. Remove the fan blade. Refer to CO-16, "
Removal and Installation (Crankshaft Driven Type)".
12. Disconnect the engine room harness from the fuse box and set it aside.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside.
15. Disconnect the engine harness grounds.
16. Disconnect the power steering reservoir tank from the engine and move it aside.
17. Disconnect the power steering oil pump from the engine. Move it aside and secure it using suitable wire or
rope. Refer to PS-21, "
Removal and Installation".
18. Remove the A/C compressor bolts and set the compressor aside. Refer to ATC-154, "
Removal and Instal-
lation for Compressor" (ATC).
19. Disconnect the brake booster vacuum line.
20. Disconnect the EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-31, "
Removal and Installation".
22. Disconnect the heater hoses at the cowl, and install plugs to avoid leakage of engine coolant.
23. Remove the A/T oil level indicator and indicator tube upper bolts.
24. Remove the front final drive assembly (4WD only). Refer to FFD-12, "
Removal and Installation".
25. Remove the exhaust manifolds. Refer to EM-21, "
Removal and Installation".
26. Install the engine slingers into the left bank cylinder head and
right bank cylinder head.
27. Remove the A/T. Refer to AT-223, "
Removal and Installation
(2WD)" or AT-225, "Removal and Installation (4WD)".
28. Lift using a hoist and secure the engine in position.
29. Remove the engine assembly from the vehicle, avoid interfer-
ence with the vehicle body.
CAUTION:
• Before and during lifting, always check if any harnesses
are left connected.
30. Remove the parts that may restrict installation of the engine to the engine stand.
NOTE:
This procedure is described assuming that you use an engine stand mounting to the surface to which the
transmission mounts.
WBIA0795E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
WBIA0715E

EM-76
< SERVICE INFORMATION >
ENGINE ASSEMBLY
a. Before removing the drive plate, put a match mark (A) on the
crankshaft and drive plate for alignment during installation.
b. Remove the drive plate.
• Holding the crankshaft pulley bolt, lock the crankshaft to remove the drive plate bolts.
• Loosen the bolts diagonally.
CAUTION:
• Be careful not to damage the drive plate. Especially
avoid deforming and damaging of the signal plate teeth
(circumference position).
• Place the drive plate with the signal plate surface facing
other than downward.
• Keep magnetic materials away from the signal plate.
CAUTION:
Use an engine stand that has a load capacity [approximately 240kg (529 lb) or more] large enough
for supporting the engine weight.
• If the load capacity of the stand is not adequate, remove the following parts beforehand to
reduce the potential risk of overturning the stand.
- Remove the fuel tube and fuel injector assembly. Refer to EM-31, "
Removal and Installation".
- Remove the intake manifold. Refer to EM-17, "
Removal and Installation".
- Remove the ignition coil. Refer to EM-28, "
Removal and Installation".
- Remove the rocker cover. Refer to EM-35, "
Removal and Installation".
- Other removable brackets.
CAUTION:
Before removing the hanging chains, make sure the engine stand is stable and there is no risk of
overturning.
31. Remove the generator. Refer to SC-22, "
Removal and Installation".
32. Remove the engine mounting insulator and bracket using power tool.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• When replacing an engine or transmission you must make sure the dowels are installed correctly
during re-assembly.
• Improper alignment caused by missing dowels may cause vibration, oil leaks or breakage of driv-
etrain components.
INSPECTION AFTER INSTALLATION
• Before starting the engine, check oil/fluid levels including engine coolant and engine oil. If the levels are
lower than required quantity, fill to the specified level. Refer to MA-10, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to the fuel piping, check for fuel
leakage at the connection points.
ALBIA0522ZZ
KBIA2491E

ENGINE ASSEMBLY
EM-77
< SERVICE INFORMATION >
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• Start engine. With engine speed increased, check again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
• Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids including
engine oil and engine coolant.
• Bleed air from passages in lines and hoses, such as in cooling system.
• After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to
specified level if necessary.
• Summary of the inspection items:
*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.Item Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Exhaust gas — Leakage —

CYLINDER BLOCK
EM-79
< SERVICE INFORMATION >
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DISASSEMBLY
NOTE:
Explained here is how to disassemble with engine stand supporting transmission surface. When using differ-
ent type of engine stand, some steps may be different.
1. Remove engine assembly and mount to engine stand. Refer to EM-74, "
Removal and Installation".
CAUTION:
Before removing the hanging chains, make sure engine stand is stable and there is no risk of over-
turning.
2. Drain engine oil. Refer to LU-9, "
Changing Engine Oil".
3. Drain engine coolant by removing the cylinder block drain plugs
“A”, “B”, “C” and “D” as shown.
4. Remove the following components and associated parts (the parts referred to in step 1 are not included
here).
• Oil pan (upper and lower) and oil strainer. Refer to EM-24, "
Removal and Installation".
• Crankshaft pulley, front cover and timing chain. Refer to EM-38, "
Removal and Installation".
• Camshaft. Refer to EM-46, "
Removal and Installation".
• Cylinder head. Refer to EM-65, "
Removal and Installation".
5. Remove knock sensor and sub harness.
CAUTION:
Carefully handle sensor, avoiding shocks.
6. Check connecting rod side clearance. Refer to EM-93, "
Inspection After Disassembly".
7. Remove piston and connecting rod assembly as follows.
a. Position the crankshaft pin corresponding to the connecting rod to be removed onto bottom dead center.
b. Remove connecting rod cap.
22. Drive plate 23. Reinforcement plate 24. Rear oil seal retainer
25. Rear oil seal 26. Transmission 27. O-ring
28. Crankshaft position sensor (POS) 29. Gasket 30. Cylinder block heater
31. Connector cap
WBIA0419E
KBIA2549E

CYLINDER BLOCK
EM-83
< SERVICE INFORMATION >
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6. Install main bearing caps.
• Align the identification number to the journal position to install.
• Install it with the front mark (indicated by the arrow) facing the
front of engine.
• Tap caps lightly to seat them in the installation position.
7. Follow the steps below to tighten each main bearing cap bolt.
a. Apply engine oil to threads and seating surfaces of bolts, and
tighten all bolts temporarily.
b. Measure tightening angle using Tool.
CAUTION:
Measure tightening angle using Tool. Do not measure visu-
ally.
• Rotate crankshaft by hand after bolts are tightened. Check if it rotates smoothly.
• Check crankshaft side clearance. Refer to EM-93, "
Inspection After Disassembly".
8. Install rear oil seal to rear oil seal retainer.
CAUTION:
Do not damage or scratch outer circumference of oil seal.
• Install new rear oil seal in the direction shown.
KBIA2533E
Main bearing cap bolts in
order of 1 to 10: 39.2 N·m (4.0 kg-m, 29 ft.-lb)
Main bearing cap sub
bolts in order of 11 to 20: 29.4 N·m (3.0 kg-m, 22 ft-lb)
PBIC0090E
Tool number : KV10112100 (BT-8653-A)
Main bearing cap bolts in
order of 1 to 10: 40°
Main bearing cap sub bolts
in order of 11 to 20: 30°
Side bolts in order of 21 to
30: 49 N·m (5.0 kg-m, 36 ft-lb)
WBIA0597E
SEM715A