2005 INFINITI QX4 service

EM-58Revision: October 2005
CYLINDER HEAD
2005 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00LME
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
CAUTION:
Leave the fuel pump fuse disconnected until step 7.
3. Remove the spark plug from each cylinder. Refer to EM-27, "
REMOVAL" .
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 EC-95, "
TROUBLE DIAGNOSIS" . 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
WBIA0605E

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CYLINDER HEAD
2005 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 the cylinder head valve guide hole using suitable tool.
4. Heat the cylinder head to 110° to 130°C (230° to 266°F) by
soaking it in heated oil.
5. Press the valve guide from the camshaft side to the dimensions
as shown.
CAUTION:
Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.
6. Ream the 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

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VALVE SEAT CONTACT

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

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

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

If not, grind to adjust the valve fit and check again. If the contact-
ing surface still has NG conditions even after the re-check,
replace the valve seat.
VALVE SEAT REPLACEMENT
When the valve seat is removed, replace it with oversized (0.5 mm, 0.020 in) valve seat.
1. Bore out the old seat until it collapses. Boring should not continue beyond the bottom face of the seat
recess in the cylinder head. Set the machine depth stop to ensure this.
2. Ream the 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 the cylinder head to 110° to 130°C (230° to 266°F) by
soaking it in heated oil.
4. Cool the valve seats well with dry ice. Force fit the valve seat into the cylinder head.
CAUTION:

Avoid directly touching cold valve seats.

Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.
5. Finish the 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

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CYLINDER BLOCK
2005 QX56
CAUTION:

Ensure the dowel pin is installed in the crankshaft.

When installing the drive plate to crankshaft, be sure to
correctly align crankshaft side dowel pin and drive plate
side dowel pin hole.

Tighten drive plate bolts crosswise several times.
NOTE:

Install the drive plate and reinforcement plate in the direction
shown.

Secure the drive plate using suitable tool.

Tighten the drive plate bolts crosswise several times.

Unlock drive plate, remove tool.
20. Installation of the remaining components is in the reverse order of removal.
How to Select Piston and Bearing EBS00LMK
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.Drive plate bolts : 88.2 N·m (9.0 kg-m, 65 ft-lb)
KBIA2494E
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———

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HOW TO SELECT PISTON
Piston Selective Fitting When New Cylinder Block is Used:

Check the cylinder bore grade on the bottom face of the cylinder
block, and select the piston of the same grade.
When Cylinder Block is Reused
1. Measure cylinder block bore diameter.
2. Determine the bore grade by comparing the measurement with the values under the “Cylinder bore diam-
eter” of the piston selection table. Use oversized piston if the clearance of standard grade piston is outside
the specified value.
Piston Selection Table
Unit: mm (in)
CAUTION:
Oversize must be used in all cylinders when using oversized parts.
NOTE:

The piston is available together with piston pin as an assembly.

The piston pin (piston pin bore) grade is provided only for the parts installed at the plant. For service parts,
no grades can be selected (only 0 grade is available).

Hone cylinder to obtain specified clearance between the piston and cylinder bore when using an over-
sized piston. Be sure to use the same oversized piston rings.
KBIA2495E
KBIA2496E
Grade number (Mark) 1 2 3
Cylinder bore diameter 98.000-98.010 (3.8583-3.8587) 98.010-98.020 (3.8587-3.8590) 93.020-98.030 (3.8590-3.8594)
Piston diameter 97.980-97.990 (3.8575-3.8579) 97.990-98.000 (3.8579-3.8583) 98.000-98.010 (3.8583-3.8587)
Piston oversize (Service) : 0.20 mm (0.0079 in)

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Undersize Bearings Usage Guide

When the specified oil clearance is not obtained with standard size connecting rod bearings, use under-
size (US) bearings.

When using undersize bearing, measure the bearing inside diameter with the bearing installed, and grind
the crankshaft pin so that the oil clearance satisfies the standard.
Bearing undersize table
Unit: mm (in)
CAUTION:
In grinding the crankshaft pin to use undersize bearings, keep
the fillet R (All crankshaft pins).
HOW TO SELECT MAIN BEARING
When New Cylinder Block and Crankshaft are Used
1. Apply the main bearing housing grade on the bottom face of the
cylinder block to the row in "Main Bearings Selection Table".
2. Apply the journal diameter grade on the crankshaft front to the
column in "Main Bearings Selection Table".
3. Read the symbol at the cross point of the selected row and column in the "Main Bearings Selection Table".
CAUTION:

Initial clearance for No. 1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection
lists for each part.

No. 1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Do not con-
fuse them.
4. Apply the symbol to the "Main Bearings Grade Table" to select.
NOTE:

Grade list applies to all journals.

Service parts are available as a set of both upper and lower.
2 1.506 - 1.509 (0.0593 - 0.0594) Green
3 1.509 - 1.512 (0.0594 - 0.0595) Yellow
Undersize Thickness
0.25 (0.0098) 1.627 - 1.635 (0.0641 - 0.0644)
Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)
PB I C 0 111E
KBIA2495E
PBIC0 110 E

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Piston and Piston Pin Clearance
(Piston pin clearance) = (Piston pin hole diameter) – (Piston pin
diameter)

If clearance exceeds specification, replace either or both the pis-
ton/piston pin assembly and the connecting rod assembly with
reference to the specification of each part.

Refer to the piston selection table to replace piston/piston pin
assembly. Refer to EM-83, "
HOW TO SELECT PISTON" .

Refer to the connecting rod bearing selection table to replace
connecting rod. Refer to EM-84, "
HOW TO SELECT CON-
NECTING ROD BEARING" .
NOTE:
The connecting rod small end grade and piston pin hole (piston
pin) grade are provided only for the parts installed at the plant.
For service parts, no grades can be selected (only 0 grade is
available).

Refer to EM-92, "Connecting Rod Bushing Oil Clearance (Small
End)" for the values for each grade at the plant.
PISTON RING SIDE CLEARANCE

Measure side clearance of the piston ring and piston ring groove
using suitable tool.

If out of specification, replace piston and/or piston ring assembly.
PISTON RING END GAP

Check if the diameter of the cylinder bore is within specification.
Refer to EM-94, "
Piston to Cylinder Bore Clearance" .

Insert the piston ring into the middle of the cylinder using the pis-
ton, and measure gap.Standard : 0.002 - 0.006 mm (0.0001 - 0.0002 in)
KBIA2496E
KBIA2536E
Standard:
Top ring : 0.035 - 0.085 mm (0.0014 - 0.0033 in)
2nd ring : 0.030 - 0.070 mm (0.0012 - 0.0028 in)
Oil ring : 0.015 - 0.050 mm (0.0006 - 0.0020 in)
Limit:
Top ring : 0.11 mm (0.0043 in)
2nd ring : 0.10 mm (0.0039 in)
SEM 02 4AA
Standard
Top ring : 0.23 - 0.33 mm (0.0091 - 0.0130 in)
2nd ring : 0.25 - 0.40 mm (0.0098 - 0.0157 in)
Oil ring : 0.20 - 0.60 mm (0.0079 - 0.0236 in)
Limit:
Top ring : 0.56 mm (0.0220 in)
2nd ring : 0.52 mm (0.0205 in)
Oil ring : 0.96 mm (0.0378 in)
PBIC0 118 E

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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 inside diameter of main bearing housing.

If out of the standard, replace cylinder block and main bearing
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 the cylinder bore for wear, out-of-round and taper at six
different 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 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