2004 INFINITI QX56 Air

CAMSHAFT
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Revision: August 20072004 QX56
3. Measure the center thickness of the removed valve lifters using
suitable tool.
4. Use the equation below to calculate valve lifter thickness for replacement.

Valve lifter thickness calculation:
Thickness of replacement valve lifter = t1+ (C1 - C2)
t1 = Thickness of removed valve lifter
C1 = Measured valve clearance
C2= Standard valve clearance:

Thickness of a new valve lifter can be identified by stamp
marks on the reverse side (inside the cylinder).
Stamp mark N788 indicates 7.88 mm (0.3102 in) in thickness.

Available thickness of valve lifter: 25 sizes with range 7.88 to
8.36 mm (0.3102 to 0.3291 in) in steps of 0.02 mm (0.0008 in)
(when manufactured at factory). Refer to EM-101, "
Available
Valve Lifter" .
5. Install the selected valve lifter.
6. Install camshaft.
7. Manually turn crankshaft pulley a few turns.
8. Make sure valve clearances for cold engine are within specifications by referring to the specified values.
9. After completing the repair, check valve clearances again with the specifications for warmed engine. Make
sure the values are within specifications.
KBIA0057E
Intake : 0.36 mm (0.0142 in)*
Exhaust : 0.37 mm (0.0146 in)*
*: Approximately 80°C (176°F)
KBIA0 119 E
Valve clearance standard:
Hot*
Intake : 0.304 - 0.416 mm (0.012 - 0.016 in)
Exhaust : 0.308 - 0.432 mm (0.012 - 0.017 in)
Cold
Intake : 0.26 - 0.34 mm (0.010 - 0.013 in)
Exhaust : 0.29 - 0.37 mm (0.011 - 0.015 in)
* : Approximately 80°C (176°F)

CYLINDER HEAD
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Revision: August 20072004 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00ILS
CHECKING COMPRESSION PRESSURE
1. Warm up engine thoroughly. Then stop engine.
2. Release fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
a. Remove fuel pump fuse, and start engine.
Refer to PG-78, "
FUSE AND RELAY BOX" or fuel pump fuse location.

Let fuel pump fuse removed until the end of step 7.
b. After engine stalls, crank it two or three times to release all fuel pressure.
3. Remove ignition coil and spark plug from each cylinder.
Refer to EM-27, "
REMOVAL" .
4. Connect engine tachometer (not required in use of CONSULT-II).
5. Install compression tester with Tool into spark plug hole.
6. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and engine rpm. Perform these steps to check each cyl-
inder.
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 specified range, check battery liquid for proper gravity. Check engine
speed again with normal battery gravity.

If compression pressure is below minimum value, check valve clearances and parts associated with
combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.

If some cylinders have low compression pressure, pour 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 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 valve in adjacent cylinders may
be damaged. Inspect and repair as required.
7. After inspection is complete, install removed parts. Installation is in the reverse order of removal.
8. Start engine, and confirm that engine runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-71, "
TROUBLE DIAGNOSIS" . Tool number : EG15050500 (J-45402)
WBIA0605E
Standard MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 300

ENGINE ASSEMBLY
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Revision: August 20072004 QX56
5. Remove the cowl extension. Refer to EI-18, "Removal and Installation" .
6. Remove engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly. Refer to EM-14, "
REMOVAL" .
8. Disconnect vacuum hose between vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-10, "
REMOVAL" .
10. Remove the drive belts. Refer to EM-12, "
Removal" .
11. Remove the fan blade. Refer to CO-13, "
REMOVAL" .
12. Disconnect the engine room harness from the fuse box and set it aside for easier work.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside for easier work.
15. Disconnect the engine harness grounds.
16. Disconnect the reservoir tank for power steering from engine and move it aside for easier work.
17. Disconnect power steering oil pump from engine. Move it from its location and secure with a rope for eas-
ier work. Refer to PS-26, "
REMOVAL" .
18. Remove the A/C compressor bolts and set aside. Refer to ATC-166, "
REMOVAL" .
19. Disconnect brake booster vacuum line.
20. Disconnect EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-29, "
REMOVAL" .
22. Disconnect the heater hoses at 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 A/T. Refer to AT-255, "
Removal and Installation (4x2)" , or AT-258, "Removal and Installation
(4x4)" .
25. Install engine slingers into left bank cylinder head and right bank
cylinder head.
26. Lift with hoist and secure the engine in position.
27. Remove engine assembly from vehicle, avoiding interference
with vehicle body.
CAUTION:

Before and during this lifting, always check if any har-
nesses are left connected.
28. Remove alternator. Refer to SC-27, "
REMOVAL" .
29. Remove 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.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
PBIC1556E

EM-72Revision: August 2007
ENGINE ASSEMBLY
2004 QX56
INSPECTION AFTER INSTALLATION

Before starting engine, check the levels of engine coolant, engine oil and working fluid. If less than
required quantity, fill to the specified level.

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
leakage 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 leakage of engine coolant, engine oil, working fluid,
fuel and exhaust gas.

Bleed air from passages in pipes and tubes of applicable lines, such as in cooling system.

After cooling down engine, again check amounts of engine coolant, engine oil and working fluid. Refill to
specified level, if necessary.

Summary of the inspection items:
*Transmission/transaxle/CVT fluid, power steering fluid, brake fluid, etc.Item Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Working fluid* Level Leakage Level
Fuel — Leakage —
Exhaust gas — Leakage —

CYLINDER BLOCK
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d. Remove the main bearing cap.

Insert bolts (2) into bolt holes, and then remove main bearing
cap by lifting up and shaking forward and backward.
15. Remove the crankshaft.
16. Remove the main bearings and thrust bearings from the cylinder block and main bearing caps.

When removing them, note the installation position. Keep them in the correct order.
17. Remove the pilot converter using Tool if necessary.
ASSEMBLY
1. Fully air-blow the coolant and oil passages in the cylinder block, cylinder bore, and crankcase to remove
any foreign material.
CAUTION:
Use goggles to protect your eyes.
2. Install each plug to the cylinder block (only screw-type plugs are
shown).

Apply liquid gasket.
Use Genuine Thread Sealant or equivalent. Refer to GI-
45, "Recommended Chemical Products and Sealants".

Replace the copper washers with new ones.

Tighten each plug as specified below.
3. Install the main bearings and thrust bearings.
a. Remove dust, dirt, and oil on the bearing mating surfaces of the
cylinder block and main bearing caps.
b. Install the thrust bearings to both sides of the No. 3 journal hous-
ing on the cylinder block and main bearing caps

Install the thrust bearings with the oil groove facing the crank-
shaft arm (outside).

Install the thrust bearings with a protrusion in the center on
the main bearing caps.
KBIA2492E
Tool number : ST16610001 (J-23907)
WBIA0596E
Part Washer Tightening torque
A Yes 53.9 N·m (5.5 kg-m, 40 ft-lb)
B No 19.6 N·m (2.0 kg-m, 15 ft-lb)
C Yes 62.7 N·m (6.4 kg-m, 46 ft-lb)
D Yes 62.7 N·m (6.4 kg-m, 46 ft-lb)
WBIA0419E
PBIC0093E

EM-82Revision: August 2007
CYLINDER BLOCK
2004 QX56
19. Install drive plate.

Align dowel pin of crankshaft rear end with pin holes of each
parts to install.

Install drive plate, reinforcement plate and pilot converter (if
not installed in step 4) as shown.

Face chamfered or rounded edge side to crankshaft.
How to Select Piston and Bearing EBS00ILY
DESCRIPTION
*For the service parts, the grade for fitting cannot be selected between a piston pin and a connecting rod.
(Only 0 grade is available.) The information at the shipment from the plant is described as a reference.

The identification grade stamped on each part is the grade for the dimension measured in new condition.
This grade cannot apply to reused parts.

For reused or repaired parts, measure the dimension accurately. Determine the grade by comparing the
measurement with the values of each selection table.

For details of the measurement method of each part, the reuse standards, and the selection method of the
selective fitting parts, refer to the text.
KBIA2494E
KBIA2537E
Connecting points Connecting parts Selection items Selection methods
Between cylinder block to
crankshaftMain bearingMain bearing grade (bearing
thickness)Determined by match of cylin-
der block bearing housing
grade (Housing inside diame-
ter) and crankshaft journal
grade (journal outside diame-
ter)
Between crankshaft to connect-
ing rodConnecting rod bearingConnecting rod bearing grade
(bearing thickness)Connecting rod bearing grade
= crankshaft pin grade (pin
diameter). No grade exists for
inside diameter of connecting
rod large end.
Between cylinder block to pis-
tonPiston and piston pin assembly.
The piston is available together
with piston pin as an assembly.Piston grade (piston diameter)Piston grade = cylinder bore
grade (diameter of bore)
*Between piston to connecting
rod———

CYLINDER BLOCK
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Inspection After DisassemblyEBS00ILZ
CRANKSHAFT END PLAY

Measure the clearance between the thrust bearings and the
crankshaft arm when the crankshaft is moved fully forward or
backward using suitable tool.

If the measured value exceeds the repair limit, replace the thrust
bearings, and measure again. If it still exceeds the repair limit,
replace the crankshaft also.
CONNECTING ROD SIDE CLEARANCE

Measure side clearance between connecting rod and crankshaft
arm using suitable tool.

If the measured value exceeds the repair limit, replace the con-
necting rod bearings, and measure again. If it still exceeds the
repair limit, replace the crankshaft also.
PISTON AND PISTON PIN CLEARANCE
Piston Pin Hole Diameter

Measure the diameter of piston pin hole using suitable tool.
Piston Pin Diameter

Measure diameter of piston pin using suitable tool.Standard : 0.10 - 0.26 mm (0.0039 - 0.0102 in)
Limit : 0.30 mm (0.0118 in)
PBIC0 114 E
Standard : 0.20 - 0.40 mm (0.0079 - 0.0157 in)
Limit : 0.40 mm (0.0157 in)
PBIC0 115 E
Standard : 21.993 - 21.999 mm (0.8659 - 0.8661 in)
PBIC0 116 E
Standard : 21.989 - 21.995 mm (0.8657 - 0.8659 in)
PBIC0 117 E

CYLINDER BLOCK
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MAIN BEARING HOUSING INSIDE DIAMETER

Install the main bearing caps with the main bearings removed,
and tighten the bolts to the specified torque. Refer to EM-77,
"ASSEMBLY" .

Measure the inside diameter of the main bearing housing.

If out of the standard, replace the cylinder block and main bear-
ing caps as an assembly.
NOTE:
These components must be replaced as a single unit, because
they were processed together.
PISTON TO CYLINDER BORE CLEARANCE
Cylinder Bore Diameter

Measure cylinder bore for wear, out-of-round and taper at six dif-
ferent points on each cylinder ("X" and "Y" directions at "A", "B"
and "C").
NOTE:
When determining cylinder bore grade, measure cylinder bore at
B position.

If the measured value exceeds the repair limit, or if there are
scratches and/or seizure on the cylinder inner wall, hone or bore the inner wall.

An oversize piston is provided. When using an oversize piston, hone the cylinder so that the clearance
between the piston and cylinder satisfies the standard.

If oversize piston is used, use it for all cylinders with oversize piston rings.
Piston Skirt Diameter

Measure piston skirt diameter using suitable tool.Standard : 68.944 - 68.968 mm (2.7143 - 2.7153 in)
PBIC1643E
PBIC0123E
Standard diameter:
98.000 - 98.030 mm (3.8583 - 3.8594 in)
Wear limit:
0.20 mm (0.0079 in)
Out-of-round (Difference between X and Y):
Limit: 0.015 mm (0.0006 in)
Taper limit (Difference between A and C):
Limit: 0.010 mm (0.0004 in)
Piston oversize Grade No. 0 (Service) : 0.20 mm (0.0079 in)
PBIC0124E
Standard : 97. 980 - 98. 010 mm (3.8575 - 3.8587 in)
PBIC0125E