2007 INFINITI QX56 service

CYLINDER HEAD
EM-69
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EM
N
P O
8. Install the valve collet using Tool.
CAUTION:
When working, take care not to damage valve lifter holes.
9. Install the valve lifters.
• Install the removed parts in their original locations.
• If installing new lifters, select the correct size lifter for proper valve clearance. Refer to EM-56, "
Va l v e
Clearance".
10. Install the spark plug tube if necessary, following the procedure below.
a. Remove any old liquid gasket adhering to the cylinder-head spark plug tube hole.
b. Apply liquid gasket to area within approximately 12 mm (0.47 in) from the edge of the spark plug tube
press-fit side.
Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-45, "
Recommended Chemical Prod-
uct and Sealant".
c. Press-fit the spark plug tube to the specified height “H” using
suitable tool.
CAUTION:
• When press-fitting, take care not to deform the spark plug
tube.
• After press-fitting, wipe off any liquid gasket protruding
onto the cylinder-head upper face.
11. Install the spark plugs.
Inspection After DisassemblyINFOID:0000000003531543
CYLINDER HEAD DISTORTION
1. Remove any oil, scale, gasket, sealant and carbon deposits from the cylinder head surface.
CAUTION:
Do not allow any debris to enter the oil or coolant passages.
2. Measure the bottom surface of the cylinder head for distortion in
six directions as shown, using suitable tools.
• If measurement exceeds the limit, replace the cylinder head.
VALVE DIMENSIONS
Tool number : KV10116200 (J-26336-A)
: KV10115900 (J-26336-20)
: KV10109220 ( — )
WBIA0578E
Standard press-fit height “H” :38.4 - 39.4 mm
(1.512 - 1.551 in)
KBIA1248E
Standard : 0.03 mm (0.0012 in)
Limit : 0.1mm (0.004 in)
PBIC0075E

EM-70
< SERVICE INFORMATION >
CYLINDER HEAD
• Check the dimensions of each valve. Refer to EM-103, "Standard
and Limit".
• If the dimensions are out of the standard, replace the valve.
VALVE GUIDE CLEARANCE
Valve Stem Diameter
Measure the diameter of the valve stem using suitable tool.
Valve Guide Inside Diameter
Measure the inside diameter of the valve guide using suitable tool.
Valve Guide Clearance
• (Valve guide clearance) = (Valve guide inside diameter) – (Valve stem diameter).
• If the calculated value exceeds the limit, replace valve and/or valve guide.
VALVE GUIDE REPLACEMENT
When the valve guide is removed, replace it with an oversized (0.2 mm, 0.008 in) valve guide.
1. To remove the valve guide, heat the cylinder head to 110° to
130°C (230° to 266°F) by soaking it in heated oil.
SEM188A
Standard
Intake : 5.965 - 5.980 mm (0.2348 - 0.2354 in)
Exhaust : 5.955 - 5.970 mm (0.2344 - 0.2350 in)
SEM938C
Standard
Intake and Exhaust : 6.000 - 6.018 mm (0.2362 - 0.2369 in)
Valve guide clearance:
Standard
Intake : 0.020 - 0.053 mm (0.0008 - 0.0021 in)
Exhaust : 0.030 - 0.063 mm (0.0012 - 0.0025 in)
Limit
Intake : 0.08 mm (0.0031 in)
Exhaust : 0.09 mm (0.0035 in)
SEM008A

CYLINDER HEAD
EM-71
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EM
N
P O
2. Remove the valve guide using suitable tool.
CAUTION:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
3. Ream the cylinder head valve guide hole using suitable tool.
4. Heat the cylinder head to 110° to 130°C (230° to 266°F) by
soaking it in heated oil.
5. Press the valve guide from the camshaft side to the dimensions
as shown.
CAUTION:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
6. Ream the cylinder head valve guide using suitable tool.
SEM931C
Valve guide hole diameter:
Standard
Intake and exhaust : 9.975 - 9.996 mm (0.3927 -
0.3935 in)
Oversize (service)
Intake and exhaust : 10.175 - 10.196 mm (0.4006
- 0.4014 in)
SEM932C
SEM008A
KBIA2530E
Valve guide hole diameter:
Intake and exhaust : 6.000 - 6.018 mm (0.2362
- 0.2369 in)
SEM932C

EM-72
< SERVICE INFORMATION >
CYLINDER HEAD
VALVE SEAT CONTACT
• After confirming that the dimensions of the valve guides and valves
are within specifications, perform this procedure.
• Apply prussian blue (or white lead) onto the contacting surface of
the valve seat to check the condition of the valve contact on the
surface.
• Check if the contact area band is continuous all around the circum-
ference.
• If not, grind to adjust the valve fit and check again. If the contacting
surface still has NG conditions even after the re-check, replace the
valve seat.
VALVE SEAT REPLACEMENT
When the valve seat is removed, replace it with oversized (0.5 mm, 0.020 in) valve seat.
1. Bore out the old seat until it collapses. Boring should not continue beyond the bottom face of the seat
recess in the cylinder head. Set the machine depth stop to ensure this.
2. Ream the cylinder head recess diameter for service valve seat.
• Be sure to ream in circles concentric to the valve guide center.
• This will enable valve seat to fit correctly.
3. Heat the cylinder head to 110° to 130°C (230° to 266°F) by
soaking it in heated oil.
4. Cool the valve seats well with dry ice. Force fit the valve seat into the cylinder head.
CAUTION:
• Avoid directly touching cold valve seats.
• Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.
5. Finish the seat to the specified dimensions using suitable tool.
Refer to EM-103, "
Standard and Limit".
CAUTION:
When using valve seat cutter, firmly grip the cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on the cutter or cutting many different times may
result in stage valve seat.
SBIA0322E
Oversize [0.5 mm (0.020 in)] (Service):
Intake : 38.500 - 38.516 mm (1.5157 - 1.5164 in)
Exhaust : 32.700 - 32.716 mm (1.2874 - 1.2880 in)
SEM795A
SEM008A
SEM934C

CYLINDER HEAD
EM-73
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EM
N
P O
6. Grind to obtain the dimensions indicated as shown.
• Using compound, grind to adjust valve fitting.
7. Check again for normal contact.
VALVE SPRING SQUARENESS
• Set try square along the side of valve spring and rotate the spring.
Measure the maximum clearance between the top face of spring
and try square.
• If measurement is not within specifications, replace the valve
spring.
VALVE SPRING DIMENSIONS AND VALVE SPRING PRESSURE LOAD
• Check the valve spring pressure at the specified spring height.
• If measurement is not within specifications, replace the valve spring.
KBIA2531E
KBIA2544E
Limit : Less than 2.2 mm (0.087 in)
PBIC0080E
Standard:
Intake and exhaust
Free height: 50.58 mm (1.9913 in)
Installation height: 37.0 mm (1.457 in)
Installation pressure: 165.8 - 187.0 N (16.9 -
19.1 kg, 37- 42 lb)
Height during valve open: 28.2 mm (1.110 in)
Load with valve open: 314.8 - 355.0 N (32.1 -
36.2 kg, 71 - 80 lb)
SEM113

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 >
C
D
E
F
G
H
I
J
K
L
MA
EM
N
P O
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