2004 INFINITI QX56 check engine

EM-42Revision: August 2007
TIMING CHAIN
2004 QX56
d. Install bolts in the numerical order shown.
e. Tighten to the specified torque.
CAUTION:
Be sure to wipe off any excessive liquid gasket leaking onto
surface mating with oil pan.
11. Install chain case cover (right bank) and (left bank) as follows:
a. Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Sealants".
CAUTION:
Both the start and end of application of liquid gasket should
be crossed at an invisible position after attaching the chain
case cover.
b. Install bolts in the numerical order shown.
12. Install the crankshaft pulley.

Install the key of the crankshaft.

Insert the pulley by lightly tapping it.
CAUTION:
Do not tap pulley on the side surface where belt is installed (outer circumference).
13. Tighten the crankshaft pulley bolt.

Lock crankshaft using suitable tool, then tighten the bolt.

Perform the following steps for angular tightening:
a. Apply engine oil onto threaded parts of bolt and seating area.
b. Select one most visible notch of the four on bolt flange. Corre-
sponding to the selected notch, put a mating mark (such as
paint) on crankshaft pulley.
14. Rotate 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 order
of removal.M6 × 50 mm (1.97 in) : No. 1, 20, 25, 26, 27
M6 × 80 mm (3.15 in) : No. 4, 5, 7
M6 × 20 mm (0.79 in) : Except the above
KBIA2478E
KBIA2481E
WBIA0468E
Crankshaft pulley bolt torque
Step 1 : 93.1 N·m (9.5 kg-m, 69 ft-lb)
Step 2 : additional 90° (angle tightening)
KBIA2519E

EM-52Revision: August 2007
CAMSHAFT
2004 QX56

Install intake and exhaust side camshaft sprocket by selec-
tively using the groove of dowel pin according to the bank.
(Common part used for both banks.)
b. Lock the hexagonal part of camshaft in the same way as for
removal, and tighten bolts.
c. Check again that the timing mating mark on timing chain and on
each sprocket are aligned.
6. Install chain tensioner with the following procedure:
NOTE:
Left bank is shown.
a. Install chain tensioner.

Compress plunger and hold it with a stopper pin when install-
ing.

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

Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Seal-
ants" .
7. Check and adjust valve clearances. Refer to EM-52, "
Va l v e
Clearance" .
8. Installation of the remaining components is in the reverse order
of removal.
Va lv e C le a ra n c eEBS00ILO
INSPECTION
NOTE:
Perform inspection as follows 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).
1. Warm up engine. Then stop engine.
2. Remove engine cover, battery cover and air duct. Refer to EM-11, "
Removal and Installation" , SC-9,
"REMOVAL" and EM-14, "Removal and Installation" .
3. Remove right bank and left bank rocker covers using power tool. Refer to EM-33, "
Removal and Installa-
tion" .
KBIA2480E
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

CAMSHAFT
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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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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

CYLINDER HEAD
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Revision: August 20072004 QX56
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 bolts with new one.

If reduction of diameter appears in a position other than d2, use
it as d2 point.
INSTALLATION
1. Install cylinder head gasket.
2. Install cylinder head. Follow the steps below and tighten the
bolts in the numerical order shown.
CAUTION:

If cylinder head bolts are re-used, check their diameters
before installation. Refer to EM-61, "
Cylinder Head Bolts
Diameter" .
a. Apply engine oil to threads and seating surface of bolts.
b. Measure tightening angle using Tool.
CAUTION:
Measure tightening angle using Tool. Do not measure visu-
ally.
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
WBIA0603E

ENGINE ASSEMBLY
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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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5. Drain engine coolant by removing cylinder block drain plug “A”,
“B”, “C” and “D” as shown.
6. Remove the following components and associated parts (The parts listed in step 3 are not included here.)

Oil pan and oil strainer. Refer to EM-22, "REMOVAL" .

Crankshaft pulley, front cover and timing chain. Refer to EM-36, "REMOVAL" .

Camshaft. Refer to EM-43, "REMOVAL" .

Cylinder head. Refer to EM-60, "REMOVAL" .
7. Remove knock sensor.
CAUTION:
Carefully handle the sensor, avoiding shocks.
8. Remove the piston and connecting rod assembly as follows.

Before removing the piston and connecting rod assembly, check the connecting rod side clearance.
Refer to EM-89, "
CONNECTING ROD SIDE CLEARANCE" .
a. Position the crankshaft pin corresponding to the connecting rod to be removed onto the bottom dead cen-
ter.
b. Remove the connecting rod cap.
c. Push the piston and connecting rod assembly out to the cylinder
head side using suitable tool.
9. Remove the connecting rod bearings.
CAUTION:
When removing them, note the installation position. Keep them in the correct order.
10. Remove the piston rings from the piston using suitable tool.
CAUTION:

When removing the piston rings, be careful not to dam-
age the piston.

Be careful not to damage piston rings by expanding them
excessively.

Before removing the piston rings, check the piston ring side
clearance. Refer to EM-90, "
PISTON RING SIDE CLEARANCE"
.
WBIA0419E
PBIC0086E
PBIC0087E