2004 INFINITI QX56 engine

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
EM-53
C
D
E
F
G
H
I
J
K
L
MA
EM
Revision: August 20072004 QX56
4. Turn crankshaft pulley in normal direction (clockwise when
viewed from engine front) to align TDC identification notch (with-
out paint mark) with timing indicator.
5. At this time, make sure both the intake and exhaust cam noses
of No. 1 cylinder (top front on left bank) face outside.

If they do not face outside, turn crankshaft pulley once more.
6. Measure valve clearances at locations marked “×” as shown in
the table below (locations indicated with black arrow) using suit-
able tool.
NOTE:
Firing order 1-8-7-3-6-5-4-2

No. 1 cylinder compression TDC

Measure valve clearance using suitable tool.
KBIA2476E
KBIA0400J
Measuring position (RH bank) No. 2 CYL No. 4 CYL No. 6 CYL No. 8 CYL
No. 1 cylinder at TDC EXH ×
INT××
Measuring position (LH bank) No. 1 CYL No. 3 CYL No. 5 CYL No. 7 CYL
No. 1 cylinder at TDCINT××
EXH××
KBIA2526E
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)
KBIA0185E

EM-54Revision: August 2007
CAMSHAFT
2004 QX56
CAUTION:
If inspection was carried out with cold engine, make sure values with fully warmed up engine
are still within specifications.
7. Turn crankshaft pulley clockwise by 270° from the position of No. 1 cylinder compression TDC to obtain
No. 3 cylinder compression TDC.
8. Measure valve clearances at locations marked “×” as shown in
the table below (locations indicated with white arrow).

No. 3 cylinder compression TDC
9. Turn crankshaft pulley clockwise by 90° from the position of No.
3 cylinder compression TDC (clockwise by 360° from the posi-
tion of No. 1 cylinder compression TDC) to measure intake and
exhaust valve clearances of No. 6 cylinder and exhaust valve
clearance of No. 2 cylinder.
10. If out of specifications, adjust as necessary. Refer to EM-54, "
ADJUSTMENT" .
ADJUSTMENT
NOTE:

Perform adjustment depending on selected head thickness of valve lifter.

The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differ-
ences caused by temperature. Use the specifications for hot engine condition to adjust.
1. Remove camshaft. Refer to EM-43, "
Removal and Installation" .
2. Remove the valve lifters at the locations that are out of specification.
Measuring position (RH bank) No. 2 CYL No. 4 CYL No. 6 CYL No. 8 CYL
No. 3 cylinder at TDC EXH ×
INT ×
Measuring position (LH bank) No. 1 CYL No. 3 CYL No. 5 CYL No. 7 CYL
No. 3 cylinder at TDCINT××
EXH××
KBIA2526E
KBIA2548E

CAMSHAFT
EM-55
C
D
E
F
G
H
I
J
K
L
MA
EM
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)

EM-56Revision: August 2007
OIL SEAL
2004 QX56
OIL SEALPFP:00100
Removal and Installation of Valve Oil SealEBS00ILP
REMOVAL
1. Remove camshaft relating to valve oil seal to be removed. Refer to EM-43, "REMOVAL" .
2. Remove valve lifters. Refer to EM-43, "
REMOVAL" .

Correctly identify location where each part is removed. Keep parts organized to avoid mixing them up.
3. Turn crankshaft until the cylinder requiring new oil seals is at TDC. This will prevent the valve from drop-
ping into the cylinder.
4. Remove valve collet using Tool.
CAUTION:
When working, take care not to damage valve lifter holes.
5. Remove valve spring retainer and valve spring.
CAUTION:
Do not remove valve spring seat from valve spring.
6. Remove valve oil seal using Tool.
INSTALLATION
Installation is in the reverse order of removal.

Install valve oil seal using Tool.

Apply new engine oil on new valve oil seal joint and seal lip.

Install valve oil seal to specified height "H".Tool number : KV10116200 (J-26336-B)
: KV10115900 (J-26336-20)
: KV10109220 ( — )
WBIA0578E
Tool number : KV10107902 (J-38959)
WBIA0478E
Tool number : KV10115600 (J-38958)
Height "H" (Without valve spring seat installed)
Intake and exhaust : 14.3 - 14.9 mm (0.563 - 0.587 in)
WBIA0490E

OIL SEAL
EM-57
C
D
E
F
G
H
I
J
K
L
MA
EM
Revision: August 20072004 QX56
Removal and Installation of Front Oil SealEBS00ILQ
REMOVAL
1. Remove the engine. Refer to EM-70, "REMOVAL" .
2. Remove crankshaft pulley. Refer to EM-35, "
TIMING CHAIN" .
3. Remove the front oil seal using a suitable tool.
CAUTION:
Be careful not to damage front cover and oil pump drive
spacer.
INSTALLATION
1. Apply new engine oil to both oil seal lip and dust seal lip of new front oil seal.
2. Install front oil seal.

Install front oil seal so that each seal lip is oriented as shown.

Press-fit until the height of front oil seal is level with the
mounting surface using suitable tool.
CAUTION:

Be careful not to damage front timing chain case and
crankshaft.

Press-fit straight and avoid causing burrs or tilting oil
seal.
3. Installation of the remaining components is in the reverse order of removal.
Removal and Installation of Rear Oil SealEBS00ILR
REMOVAL
1. Remove transmission assembly. Refer to AT-255, "REMOVAL" (4x2 models) or AT-258, "REMOVAL"
(4x4 models).
a. Remove drive plate.

Holding crankshaft pulley bolts, lock crankshaft to remove drive plate bolts.

Remove the bolts diagonally.
CAUTION:

Be careful not to damage drive plate. Especially avoid deforming and damaging of signal
plate teeth (circumference position).

Place the drive plate with signal plate surface facing other than downward.

Keep magnetic materials away from signal plate.
SBIA0359E
SEM 71 5A
PBIC2931E

EM-58Revision: August 2007
OIL SEAL
2004 QX56
b. Remove engine rear plate.
2. Remove the rear oil seal using a suitable tool.
CAUTION:
Be careful not to damage crankshaft and oil seal retainer
surface.
INSTALLATION
1. Apply new engine oil to both oil seal lip and dust seal lip of new rear seal.
2. Install rear oil seal.

Install rear oil seal so that each seal lip is oriented as shown.

Press-fit rear oil seal using suitable tool.
CAUTION:

Be careful not to damage crankshaft and cylinder
block.

Press-fit oil seal straight to avoid causing burrs or tilt-
ing.

Do not touch grease applied onto oil seal lip.

Do not damage or scratch the outer circumference of
the rear oil seal.

Tap until flattened with the front edge of the oil seal retainer.
3. Installation of the remaining components is in the reverse order of removal.
WBIA0437E
SEM 71 5A
PBIC2933E

CYLINDER HEAD
EM-59
C
D
E
F
G
H
I
J
K
L
MA
EM
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