INFINITI QX56 2006 Factory Service Manual

EM-70Revision: November 2009
CYLINDER HEAD
2006 QX56
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.
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.
SEM008A
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

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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.
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 cir-
cumference.

If not, grind to adjust the valve fit and check again. If the contact-
ing 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.
KBIA2530E
Valve guide hole diameter:
Intake and exhaust : 6.000 - 6.018 mm (0.2362 - 0.2369 in)
SEM932C
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

EM-72Revision: November 2009
CYLINDER HEAD
2006 QX56
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-108, "
Va l v e S e a t" .
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.
6. Grind to obtain the dimensions indicated as shown.

Using compound, grind to adjust valve fitting.
7. Check again for normal contact. Refer to EM-71, "
VALVE SEAT CONTACT" .
SEM008A
SEM934C
KBIA2531E
KBIA2544E

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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.Limit : Less than 2.2 mm (0.087 in)
PBIC0080E
Standard:
Intake and exhaustFree 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-74Revision: November 2009
ENGINE ASSEMBLY
2006 QX56
ENGINE ASSEMBLYPFP:10001
Removal and InstallationEBS00RFH
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-41, "Garage Jack and
Safety Stand" .
REMOVAL
Preparation
1. Drain the engine coolant. Refer to CO-11, "DRAINING ENGINE COOLANT" .
2. Partially drain the A/T fluid. Refer to AT- 1 2 , "
Changing Automatic Transmission Fluid (ATF)" .
3. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE"
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
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4. Remove the engine hood. Refer to BL-13, "Removal and Installation of Hood Assembly" .
5. Remove the cowl extension. Refer to EI-18, "
Removal and Installation" .
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-14, "
Removal and Installation" .
10. Remove the drive belts. Refer to EM-13, "
Removal and Installation" .
11. Remove the fan blade. Refer to CO-17, "
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-175, "
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- 2 4 3 , "
Removal and Installation
(2WD)" or AT- 2 4 6 , "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.
a. Remove the drive plate.

Holding the crankshaft pulley bolt, lock the crankshaft to remove the drive plate bolts.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
WBIA0715E

EM-76Revision: November 2009
ENGINE ASSEMBLY
2006 QX56

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 fac-
ing 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 alternator. Refer to SC-25, "
REMOVAL" .
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-11, "
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.

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 includ-
ing 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:
KBIA2491E

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*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.Item
Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakageLeakage
Exhaust gas —Leakage —

EM-78Revision: November 2009
CYLINDER BLOCK
2006 QX56
CYLINDER BLOCKPFP:11010
Disassembly and AssemblyEBS00RFI
WBIA0471E

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Revision: November 2009 2006 QX56
* Refer to GI-46, "Recommended Chemical Products and Sealants" .
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-8, "
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-37, "Removal and Installation" .

Camshaft. Refer to EM-46, "Removal and Installation" .

Cylinder head. Refer to EM-64, "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-94, "
CONNECTING ROD SIDE CLEARANCE" .
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.
1. Knock sensor sub-harness 2. Knock sensor 3. Cylinder block
4. Main bearing upper 5. Top ring 6. Second ring
7. Oil ring 8. Crankshaft key 9. Piston
10. Connecting rod 11. Snap ring 12. Piston pin
13. Connecting rod bearing 14. Connecting rod bearing cap 15. Main bearing cap
16. Thrust bearing lower 17. Main bearing lower 18. Crankshaft
19. Pilot converter 20. Thrust bearing upper 21. Side bolt
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