engine INFINITI QX56 2008 Factory Service Manual

CYLINDER HEADEM-69
< ON-VEHICLE REPAIR >
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• Cylinder head bolts are tightened by plastic zone tightening
method. Whenever the size difference between d1 and d2 exceeds
the limit, replace the bolt with a new one.
• If reduction of diameter appears in a position other than d2, use it as d2 point.
INSTALLATION
1. Install a new cylinder head gasket.
2. Install the cylinder head. Follow the steps below to tighten the bolts in the numerical order shown.
CAUTION:
• If cylinder head bolts are re-used, check their diameters
before installation. Refer to "Cylinder Head Bolts Diame-
ter".
a. Apply engine oil to threads and seating surface of the bolts.
b. Measure the tightening angle using Tool. CAUTION:
Measure the tightening angl e using Tool. Do not measure
visually.
3. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
• Before starting engine, check oil/fluid levels incl uding engine coolant and engine oil. If less than required
quantity, fill to the specified level. Refer to MA-12, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak-
age at 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 leak age 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 engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec- ified level, if necessary.
• Summary of the inspection items: Limit (d1 - d2) : 0.23 mm (0.0091 in)
KBIA0189E
PBIC0068E
Step a : 44.1 N·m (4.5 kg-m, 33 ft-lb)
Step b : 70°
clockwise
Step c : Loosen in the reverse order of tightening.
Step d : 44.1 N·m (4.5 kg-m, 33 ft-lb)
Step e : 60 ° clockwise
Step f : 60° clockwise
WBIA0603E
Tool number : KV10112100 (BT-8653-A)
Revision: March 2010 2008 QX56

EM-70
< ON-VEHICLE REPAIR >
CYLINDER HEAD
*Power steering fluid, brake fluid, etc.
Disassembly and AssemblyINFOID:0000000001538829
DISASSEMBLY
1. Remove the spark plug. Refer to EM-16, "Removal and Installation".
2. Remove the valve lifter. • Identify the installation positions, and store them without mixing them up.
Item Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Transmission/
transaxle fluid A/T and CVT Models
LeakageLevel/Leakage Leakage
M/T Models Level/Leakage LeakageLevel/Leakage
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakage Leakage
Exhaust gas —Leakage —
1. Spark plug 2. Valve lifter3. Valve collet
4. Valve spring retainer 5. Valve spring6. Valve spring seat
7. Valve oil seal 8. Valve guide9. Valve seat
10. Valve (INT) 11. Valve (EXH)12. Cylinder head (LH bank)
13. Spark plug tube 14. Cylinder head (RH bank)
WBIA0470E
Revision: March 2010 2008 QX56

CYLINDER HEADEM-71
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3. Remove the valve collet using Tools.
CAUTION:
When working, take care not to damage valve lifter holes.
4. Remove the valve spring retainer, valve spring and valve spring seat.
5. Inspect the valve guide clearance. Refer to EM-72, "
Inspection After Disassembly".
6. Push the valve stem to the combustion chamber side, and remove the valve. • Identify the installation positions, and store them without mixing them up.
7. Remove the valve oil seal using Tool.
8. Replace the valve seat if necessary. Refer to EM-72, "
Inspection After Disassembly".
9. Replace the valve guide if necessary. Refer to EM-72, "
Inspection After Disassembly".
10. Remove the spark plug tube, as necessary. • Remove the spark plug tube out of the cylinder head using suitable tool.
CAUTION:
• Do not damage the cylinder head.
• Do not remove the spark plug tube unless absolutely necessary. Once removed, the spark plug tube will be deformed and cannot be reused.
ASSEMBLY
1. Install the valve guide if necessary. Refer to EM-72, "Inspection After Disassembly".
2. Install the valve seat if necessary. Refer to EM-72, "
Inspection After Disassembly".
3. Install the valve oil seal using Tool.
• Apply new engine oil on the new valve oil seal joint and seallip.
• Install the valve oil seal to the specified height "H".
4. Install the valves in their original position.
5. Install the valve spring seats. Tool number
: KV10116200 (J-26336-A)
: KV10115900 (J-26336-20)
: KV10109220 ( — )
Tool number : KV10107902 (J-38959)
WBIA0578E
WBIA0478E
Tool number : KV10115600 (J-38958)
Height "H" (without valve spring installed) Intake and exhaust : 14.3 - 14.9 mm (0.563 - 0.587 in)
WBIA0490E
Revision: March 2010 2008 QX56

EM-78
< REMOVAL AND INSTALLATION >
ENGINE ASSEMBLY
REMOVAL AND INSTALLATION
ENGINE ASSEMBLY
Removal and InstallationINFOID:0000000001538831
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 exh aust system and engine coolant are cooled sufficiently.
• If items or work required are no t covered by the engine section, follow the applicable procedures.
• Always use the support poin t 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-30, "
Garage Jack and
Safety Stand".
REMOVAL
Preparation
1. Drain the engine coolant. Refer to CO-11, "Changing Engine Coolant".
2. Partially drain the A/T fluid. Refer to TM-180, "
Changing the A/T Fluid (ATF)".
3. Release the fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
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
Revision: March 2010 2008 QX56

ENGINE ASSEMBLYEM-79
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4. Remove the engine hood. Refer to
DLK-224, "Removal and Installation of Hood Assembly".
5. Remove the cowl extension. Refer to EXT-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-25, "
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-15, "
Removal and Installation".
10. Remove the drive belts. Refer to EM-13, "
Removal and Installation".
11. Remove the fan blade. Refer to CO-18, "
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 t ank 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 ST-26, "
Removal and Installation".
18. Remove the A/C compressor bolts and set the compressor aside. Refer to HA-31, "
Removal and Installa-
tion 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-40, "
Removal and Installation".
22. Disconnect the heater hoses at the cowl, and in stall 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 DLN-212, "
Removal and Installation".
25. Remove the exhaust manifolds. Refer to EM-30, "
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 TM-214, "
Removal and Installation
(2WD)" or TM-216, "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 harnessesare 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
Revision: March 2010 2008 QX56

EM-80
< REMOVAL AND INSTALLATION >
ENGINE ASSEMBLY
a. Before removing the drive plate, put a match mark (A) on thecrankshaft 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. Especiallyavoid deforming and damaging of the signal plate teeth
(circumference position).
• Place the drive plate with th e 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 [a pproximately 240kg (529 lb) or more] large enough
for supporting the engine weight.
• If the load capacity of the stand is not adeq uate, 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-40, "
Removal and Installation".
- Remove the intake manifold. Refer to EM-26, "
Removal and Installation".
- Remove the ignition coil. Refer to EM-37, "
Removal and Installation".
- Remove the rocker cover. Refer to EM-38, "
Removal and Installation".
- Other removable brackets.
CAUTION:
Before removing the hanging chains, make sure th e engine stand is stable and there is no risk of
overturning.
31. Remove the generator. Refer to CHG-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 mu st make sure the dowels are installed correctly
during re-assembly.
• Improper alignment caused by mi ssing dowels may cause vibration, oil leaks or breakage of driv-
etrain components.
INSPECTION AFTER INSTALLATION
• Before starting engine, check oil/fluid levels incl uding engine coolant and engine oil. If less than required
quantity, fill to the specified level. Refer to MA-12, "
Fluids and Lubricants".
• Use procedure below to check for fuel leakage.
• Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leak- age at connection points.
ALBIA0522ZZ
KBIA2491E
Revision: March 2010 2008 QX56

ENGINE ASSEMBLYEM-81
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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 leak
age 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 engine, again check oil/fluid levels including engine oil and engine coolant. Refill to spec- ified level, if necessary.
• Summary of the inspection items:
*Power steering fluid, brake fluid, etc. Item
Before starting engine Engine runningAfter engine stopped
Engine coolant LevelLeakage Level
Engine oil LevelLeakage Level
Transmission/
transaxle fluid A/T and CVT Models
LeakageLevel/Leakage Leakage
M/T Models Level/Leakage LeakageLevel/Leakage
Other oils and fluids* LevelLeakage Level
Fuel LeakageLeakageLeakage
Exhaust gas —Leakage —
Revision: March 2010 2008 QX56

EM-82
< DISASSEMBLY AND ASSEMBLY >
ENGINE UNIT
DISASSEMBLY AND ASSEMBLY
ENGINE UNIT
Disassembly and AssemblyINFOID:0000000001538832
1. Knock sensor sub-harness 2. Knock sensor3. Cylinder block
4. Main bearing upper 5. Top ring6. Second ring
7. Oil ring 8. Crankshaft key9. Piston
10. Connecting rod 11. Snap ring12. Piston pin
13. Connecting rod bearing 14. Connecting rod bearing cap 15. Main bearing cap
WBIA0471E
Revision: March 2010 2008 QX56

ENGINE UNITEM-83
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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-78, "
Removal and Installation".
CAUTION:
Before removing the hanging chains, make sure engi ne 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-33, "
Removal and Installation".
• Crankshaft pulley, front cover and timing chain. Refer to EM-45, "
Removal and Installation".
• Camshaft. Refer to EM-53, "
Removal and Installation".
• Cylinder head. Refer to EM-68, "
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-90, "
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.
16. Thrust bearing lower 17. Main bearing lower18. Crankshaft
19. Pilot converter 20. Thrust bearing upper21. Side bolt
22. Drive plate 23. Reinforcement plate24. Rear oil seal retainer
25. Rear oil seal 26. Transmission27. O-ring
28. Crankshaft position sensor (POS) 29. Gasket 30. Cylinder block heater
31. Connector cap
WBIA0419E
KBIA2549E
Revision: March 2010 2008 QX56

EM-84
< DISASSEMBLY AND ASSEMBLY >
ENGINE UNIT
c. Push the piston and connecting rod assembly out to the cylinderhead side using suitable tool.
8. Remove connecting rod bearings. CAUTION:
When removing them, note th e installation position. Keep them in the correct order.
9. Check piston ring side clearance. Refer to EM-90, "
Inspection After Disassembly".
10. Remove piston rings from piston using suitable tool. CAUTION:
• Do not damage piston.
• Do not damage piston rings by expanding them exces-sively.
11. Remove piston from connecting rod as follows.
a. Remove snap ring using suitable tool.
b. Heat piston to 60 ° to 70° C (140° to 158°F) using suitable tool.
PBIC0086E
PBIC0087E
PBIC0260E
PBIC0261E
Revision: March 2010 2008 QX56