check 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-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
< REMOVAL AND INSTALLATION >
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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

ENGINE UNITEM-83
< DISASSEMBLY AND ASSEMBLY >
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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

ENGINE UNITEM-87
< DISASSEMBLY AND ASSEMBLY >
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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 thefront 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 usin g 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-90, "
Inspection After Disassembly".
8. Install rear oil seal to rear oil seal retainer. CAUTION:
Do not damage or scratch ou ter 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
Revision: March 2010
2008 QX56

ENGINE UNITEM-89
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12. Install the connecting rod bearings to the connecting rod and
connecting rod cap.
• When installing the connecting rod bearings, apply engine oilto the bearing surface (inside). Do not apply oil to the back
surface, but thoroughly clean it.
• When installing, align the connecting rod bearing stopper pro-
trusion with the cutout of the connecting rod to install.
• Check that the oil holes on the connecting rod and those on the corresponding bearing are aligned.
13. Install the piston and connecting rod assembly to the crankshaft using Tool.
• Position the crankshaft pin corresponding to the connecting
rod to be installed onto bottom dead center.
• Apply engine oil sufficiently to the cylinder bore, piston, and
crankshaft pin.
• Match the cylinder position with the cylinder No. on the con- necting rod to install.
• Install the piston with the front mark on the piston crown facing the front of the engine.
CAUTION:
Be careful not to damage the crankshaft pin, resu lting from an interference of the connecting rod
big end.
14. Install connecting rod cap. • Match the stamped cylinder number marks on the connectingrod with those on the cylinder cap to install.
15. Tighten connecting rod bolts using Tool. • Apply engine oil to threads and seats of connecting rod bolts.
• After tightening bolts, make sure the crankshaft rotatessmoothly.
• Check connecting rod side clearance. Refer to EM-90,
"Inspection After Disassembly".
PBIC0266E
Tool number : EM03470000 (J-8037)
WBIA0626E
KBIA2536E
Tool number : KV10112100 (BT-8653-A)
Connecting rod bolts
Step 1 : 19.6 N·m (1.5 kg-m, 11 ft-lb)
Step 2: 90° clockwise
WBIA0627E
Revision: March 2010 2008 QX56

EM-92
< DISASSEMBLY AND ASSEMBLY >
ENGINE UNIT
(Piston pin clearance) = (Piston pin hole diameter) – (Piston pin
diameter)
• If clearance exceeds specification, replace either or both the pis-
ton/piston pin assembly and the connecting rod assembly with ref-
erence to the specification of each part.
• Use the piston selection table to replace piston/piston pin assem-
bly. Refer to EM-101, "
How to Select Piston and Bearing".
• Use the connecting rod bearing selection table to replace connect- ing rod. Refer to EM-101, "
How to Select Piston and Bearing".
NOTE:
The connecting rod small end grade and piston pin hole (piston
pin) grade are provided only for the parts installed at the plant. For
service parts, no grades can be selected (only 0 grade is avail-
able).
• Follow the "Connecting Rod Bushing Oil Clearance (Small End)" procedure for the values for each grade at the plant.
PISTON RING SIDE CLEARANCE
• Measure side clearance of the piston ring and piston ring grooveusing suitable tool.
• If out of specification, replac e piston and/or piston ring assembly.
PISTON RING END GAP
• Check if the diameter of the cyli nder bore is within specification.
Follow the "Piston to Cylinder Bore Clearance" procedure.
• Insert the piston ring into the middle of the cylinder using the pis- ton, and measure the gap.
• If out of specification, replace pi ston ring. If the gap still exceeds the li mit even with a new ring, re-bore the
cylinder and use oversized piston and piston ring. Standard : 0.002 - 0.006 mm (0.0001 - 0.0002 in)
KBIA2496E
KBIA2536E
Standard:
Top ring : 0.035 - 0.085 mm (0.0014 - 0.0033 in)
2nd ring : 0.030 - 0.070 mm (0.0012 - 0.0028 in)
Oil ring : 0.015 - 0.050 mm (0.0006 - 0.0020 in)
Limit: Top ring : 0.11 mm (0.0043 in)
2nd ring : 0.10 mm (0.0039 in)
SEM024AA
Standard Top ring : 0.23 - 0.33 mm (0.0091 - 0.0130 in)
2nd ring : 0.25 - 0.40 mm (0.0098 - 0.0157 in)
Oil ring : 0.20 - 0.60 mm (0.0079 - 0.0236 in)
Limit: Top ring : 0.56 mm (0.0220 in)
2nd ring : 0.52 mm (0.0205 in)
Oil ring : 0.96 mm (0.0378 in)
PBIC0118E
Revision: March 2010 2008 QX56