2006 INFINITI QX56 check engine

EM-34Revision: November 2009
FUEL INJECTOR AND FUEL TUBE
2006 QX56

Make sure that O-ring and its mating part are free of foreign material.

When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring.

If O-ring was stretched while it was being attached, do not insert it quickly into fuel tube.

Insert new O-ring straight into fuel tube. Do not twist it.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing the fuel tubes, make sure there are no fuel leaks at the connections using the following steps.
1. Apply fuel pressure to the fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at the connections.
NOTE:
Use mirrors for checking on hidden points.
2. Start the engine and rev it up and check for fuel leaks at the connections.
CAUTION:
Do not touch the engine immediately after stopping, as engine becomes extremely hot.

TIMING CHAINEM-45
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a. Apply engine oil onto the threaded parts of the bolt and seating area.
b. Select the one most visible notch of the four on the bolt flange.
Corresponding to the selected notch, put a alignment mark
(such as paint) on the crankshaft pulley.
14. Rotate the crankshaft pulley in normal direction (clockwise when viewed from engine front) to check for parts interference.
15. Installation of the remaining components is in the reverse of order of removal.Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90
° (angle tightening)
KBIA2519E

CAMSHAFTEM-55
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5. Install the camshaft sprockets using the following procedure:

A: LH bank shown
a. Install the camshaft sprockets aligning them with the matching marks painted (B) on the timing chain (C) when removed. Align
the camshaft sprocket key groove with the dowel pin on the
camshaft front edge at the same time. Then temporarily tighten
camshaft sprocket bolts.

Install the intake and exhaust side camshaft sprockets by
selectively using the groove of the dowel pin according to the
bank. (Common part used for both banks.)

A: Intake (I)

B: Exhaust (E)

R: for RH bank

L: for LH bank
b. Lock the hexagonal part of the camshaft in the same way as for removal, and tighten the camshaft sprocket bolts.
c. Check again that the timing alignment mark on the timing chain and on each sprocket are aligned.
6. Install the chain tensioner using the following procedure: NOTE:
LH is shown.
a. Install the chain tensioner.

Compress the plunger and hold it using a stopper pin when
installing.

Loosen the slack guide side timing chain by rotating the cam-
shaft hexagonal part if mounting space is small.
b. Remove the stopper pin and release the plunger, and then apply tension to the timing chain.
c. Install the RH bank timing chain tensioner cover onto the front cover.

Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants"
.
7. Check and adjust valve clearances. Refer to EM-55, "
Va l v e
Clearance" .
8. Installation of the remaining components is in the reverse order of removal.
Va l v e C l e a r a n c eEBS00RF9
INSPECTION
NOTE:
Perform the following inspection after removal, installation or replacement of camshaft or valve-related parts,
or if there are unusual engine conditions due to changes in valve clearance over time (starting, idling, and/or
noise).
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WBIA0700E
Chain tensioner bolts : 6.9 N·m (0.70 kg-m, 61 in-lb)
Tensioner cover bolts : 9.0 N·m (0.92 kg-m, 80 in-lb)KBIA2479E
KBIA2547E

CAMSHAFTEM-59
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5. Install the selected valve lifter.
6. Install the camshaft.
7. Manually turn the crankshaft pulley a few turns.
8. Make sure the valve clearances for a cold engine are within specifications by referring to the specified val-
ues.
9. After completing the repair, check the valve clearances again with the specifications for a warmed engine. Make sure the values are within specifications. Refer to EM-105, "
Valve Clearance" .

CYLINDER HEADEM-63
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Revision: November 2009 2006 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00RFD
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
CAUTION:
If CONSULT-II is not used to release fuel pressure leave the fuel 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, check 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, the 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. Replace the valve or valve seat accordingly.

If two adjacent cylinders have respectively low compression 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 LAN-26, "
CAN COMMUNICATION" .
Tool number : EG15050500 (J-45402)
Standard
MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 200
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CYLINDER HEADEM-65
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INSPECTION AFTER REMOVAL
Cylinder Head Bolts Diameter

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 EM-65, "
Cylinder Head Bolts
Diameter" .
a. Apply engine oil to threads and seating surface of the bolts.
b. Measure the tightening angle using Tool.
CAUTION:
Measure the tightening angle using Tool. Do not measure
visually.
3. Installation of the remaining components is in the reverse order of removal. Limit (d1 - d2) : 0.18 mm (0.0071 in)
KBIA0189E
Step a : 98.1 N·m (10 kg-m, 72 ft-lb)
Step b :Loosen in the reverse order of tightening.
Step c : 44.1 N·m (4.5 kg-m, 33 ft-lb)
PBIC0068E
Tool number
: KV10112100 (BT-8653-A)
Step d : 60 ° clockwise
Step e : 60 ° clockwise
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ENGINE ASSEMBLYEM-75
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Revision: November 2009 2006 QX56
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)
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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