2004 INFINITI QX56 Meter

CAMSHAFT
EM-45
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Revision: August 20072004 QX56
NOTE:

Stop plunger in the fully extended position using return-proof clip
1 if stopper pin is removed.

Push the plunger 2 into the tensioner body while squeezing the
return-proof clip 1. Secure it using stopper pin 3.
6. Remove the right chain tensioner cover from the front cover
using Tool.
CAUTION:
Use care not to damage mating surfaces.
7. Remove chain tensioner on right bank using the following steps.
WAR NIN G:
Plunger, spring, and spring seat pop out when squeezing return-proof clip without holding
plunger head. It may cause serious injuries. Always hold plunger head when removing.
a. Squeeze return-proof clip ends using suitable tool and push the
plunger into the tensioner body.
b. Secure plunger using stopper pin.

Stopper pin is made from hard wire approximately 1 mm (0.04
in) in diameter.
c. Remove the bolts and the right bank chain tensioner.
NOTE:
If it is difficult to push plunger on right bank chain tensioner,
remove the plunger under extended condition.
KBIA2483E
Tool number : KV10111100
KBIA2521E
KBIA2479E
KBIA2484E

CAMSHAFT
EM-47
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Revision: August 20072004 QX56
INSPECTION AFTER REMOVAL
Camshaft Runout
1. Put V block on precise flat work bench, and support No. 1 and
No. 5 journal of camshaft.
2. Set dial gauge vertically to No. 3 journal.
3. Turn camshaft to one direction with hands, and measure cam-
shaft runout on dial gauge.

1/2 of runout is bend.

If measurement exceeds specification, replace camshaft.
Camshaft Cam Height

Measure camshaft cam height.

If measurement is not within the specifications, replace cam-
shaft.
Camshaft Journal Clearance
Camshaft Journal Diameter

Measure diameter of camshaft journal.
Camshaft Bracket Inner Diameter

Tighten camshaft bracket bolt to specified torque.

Measure inner diameter of camshaft bracket.
Calculation of Camshaft Journal Clearance
(Journal clearance) = (camshaft bracket inner diameter) – (camshaft
journal diameter)

If measurement is not within specification, replace either or both
camshaft and cylinder head.
NOTE:
Inner diameter of camshaft bracket is manufactured together with cylinder head. Replace the whole cylin-
der head assembly.Camshaft runout : Less than 0.02 mm (0.0008 in)
EMK0641D
Standard cam height
(intake & exhaust): 44.465 - 44.655 mm
(1.7506 - 1.7581 in)
Cam wear limit
(intake & exhaust): 0.02 mm (0.0008 in)
PBIC0039E
Standard diameter : 25.953 - 25.970 mm
(1.0218 - 1.0224 in)
PBIC0040E
Standard : 26.000 - 26.021 mm (1.0236 - 1.0244 in)
Standard : 0.030 - 0.068 mm (0.0012 - 0.0027 in)
PBIC1645E

CAMSHAFT
EM-49
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Revision: August 20072004 QX56
Valve Lifter Clearance
Valve Lifter Diameter

Measure diameter of valve lifter using suitable tool.
Valve Lifter Hole Diameter

Measure diameter of valve lifter hole of cylinder head using suit-
able tool.
Calculation of Valve Lifter Clearance
(Valve lifter clearance) = (valve lifter hole diameter) – (valve lifter
diameter)

If measurement is not within specification, referring to each
specification of valve lifter diameter and hole diameter, replace
either or both valve lifter and cylinder head.
INSTALLATION
1. Install valve lifters if removed.

Install removed parts in their original locations.
2. Install camshafts. Refer to the table below for identification of
right and left bank, and intake and exhaust.

Install so that dowel pin at the front of camshaft face is in the
direction shown.Standard : 33.977 - 33.987 mm (1.3377 - 1.3381 in)
JEM798G
Standard : 34.000 - 34.016 mm (1.3386 - 1.3392 in)
Standard : 0.013 - 0.039 mm (0.0005 - 0.0015 in)
PBIC0043E
Bank INT EXHIdentification
paint (front)Identification
paint (rear)Identification
rib
RHINT White — Yes.
EXH — Light blue Yes.
LHINT White — No.
EXH — Light blue No.
KBIA2523E
KBIA2524E

CYLINDER HEAD
EM-59
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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

CYLINDER HEAD
EM-61
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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

EM-66Revision: August 2007
CYLINDER HEAD
2004 QX56
VALVE GUIDE CLEARANCE
Valve Stem Diameter
Measure diameter of valve stem using suitable tool.
Valve Guide Inside Diameter
Measure inside diameter of valve guide using suitable tool.
Valve Guide Clearance

(Valve guide clearance) = (Valve guide inside diameter) – (Valve stem diameter).

If the calculated value exceeds the limit, replace valve and/or valve guide. When the valve guide must be
replaced, refer to EM-66, "
VALVE GUIDE REPLACEMENT" .
VALVE GUIDE REPLACEMENT
When valve guide is removed, replace with oversized (0.2 mm, 0.008 in) valve guide.
1. To remove valve guide, heat cylinder head to 110° to 130°C
(230° to 266°F) by soaking in heated oil. Standard
Intake : 5.965 - 5.980 mm (0.2348 - 0.2354 in)
Exhaust : 5.955 - 5.970 mm (0.2344 - 0.2350 in)
SEM 93 8C
Standard
Intake and Exhaust : 6.000 - 6.018 mm (0.2362 - 0.2369 in)
Valve guide clearance:
Standard
Intake : 0.020 - 0.053 mm (0.0008 - 0.0021 in)
Exhaust : 0.030 - 0.063 mm (0.0012 - 0.0025 in)
Limit
Intake : 0.08 mm (0.0031 in)
Exhaust : 0.09 mm (0.0035 in)
SEM 00 8A

CYLINDER HEAD
EM-67
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Revision: August 20072004 QX56
2. Remove the valve guide using suitable tool.
CAUTION:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
3. Ream cylinder head valve guide hole using suitable tool.
4. Heat cylinder head to 110 to 130°C (230 to 266°F) by soaking in
heated oil.
5. Press valve guide from camshaft side to dimensions as shown.
CAUTION:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
6. Ream cylinder head valve guide hole using suitable tool.
SEM 93 1C
Valve guide hole diameter:
Standard
Intake and exhaust : 9.975 - 9.996 mm (0.3927 -
0.3935 in)
Oversize (service)
Intake and exhaust : 10.175 - 10.196 mm
(0.4006 - 0.4014 in)
SEM 93 2C
SEM 00 8A
KBIA2530E
Valve guide hole diameter:
Intake and exhaust : 6.000 - 6.018 mm
(0.2362 - 0.2369 in)
SEM 93 2C

EM-68Revision: August 2007
CYLINDER HEAD
2004 QX56
VALVE SEAT CONTACT

After confirming that the dimensions of valve guides and valves
are within specifications, perform this procedure.

Apply prussian blue (or white lead) onto contacting surface of
valve seat to check the condition of the valve contact on the sur-
face.

Check if the contact area band is continuous all around the cir-
cumference.

If not, grind to adjust valve fitting and check again. If the contact-
ing surface still has NG conditions even after the re-check,
replace valve seat.
VALVE SEAT REPLACEMENT
When valve seat is removed, replace with oversized (0.5 mm, 0.020 in) valve seat.
1. Bore out old seat until it collapses. Boring should not continue beyond the bottom face of the seat recess
in cylinder head. Set the machine depth stop to ensure this.
2. Ream cylinder head recess diameter for service valve seat.

Be sure to ream in circles concentric to the valve guide center.

This will enable valve seat to fit correctly.
3. Heat cylinder head to 110 to 130°C (230 to 266°F) by soaking in
heated oil.
4. Provide valve seats cooled well with dry ice. Force fit valve seat into cylinder head.
CAUTION:

Avoid directly touching cold valve seats.

Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.
5. Finish seat to the specified dimensions using suitable tool. Refer
to EM-103, "
Valve Seat" .
CAUTION:
When using valve seat cutter, firmly grip the cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on the cutter or cutting many different times may
result in stage valve seat.
SBIA0322E
Oversize [0.5 mm (0.020 in)] (Service):
Intake : 38.500 - 38.516 mm (1.5157 - 1.5164 in)
Exhaust : 32.700 - 32.716 mm (1.2874 - 1.2880 in)
SEM 79 5A
SEM 00 8A
SEM 93 4C