2006 INFINITI QX56 service

EM-8Revision: November 2009
PREPARATION
2006 QX56
Commercial Service ToolsEBS00RER
(Kent-Moore No.)
Tool nameDescription
Power tool Loosening bolts and nuts
Spark plug wrench Removing and installing spark plug
(J-24239-01)
Cylinder head bolt wrench Loosening and tightening cylinder head bolt,
and use with angle wrench [SST:
KV10112100 (BT-8653-A)]
a: 13 (0.51) dia.
b: 12 (0.47)
c: 10 (0.39)
Unit: mm (in)
Valve seat cutter set Finishing valve seat dimensions
Pulley puller Removing crankshaft pulley
Piston ring expander Removing and installing piston ring
Valve guide drift Removing and installing valve guide
Intake & Exhaust:
a: 9.5 mm (0.374 in) dia.
b: 5.5 mm (0.217 in) dia.
PBIC0190E
S-NT047
NT583
S-NT048
ZZA0010D
S-NT030
S-NT015

CYLINDER HEADEM-63
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Revision: November 2009 2006 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00RFD
CHECKING COMPRESSION PRESSURE
1. Warm up the engine thoroughly. Then stop the engine.
2. Release the fuel pressure. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
CAUTION:
If CONSULT-II is not used to release fuel pressure leave the fuel pump fuse disconnected until
step 7.
3. Remove the spark plug from each cylinder. Refer to EM-29, "
Removal and Installation" .
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 LAN-26, "
CAN COMMUNICATION" .
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

EM-70Revision: November 2009
CYLINDER HEAD
2006 QX56
VALVE GUIDE REPLACEMENT
When the valve guide is removed, replace it with an oversized (0.2 mm, 0.008 in) valve guide.
1. To remove the valve guide, heat the cylinder head to 110° to
130° C (230 ° to 266 °F) by soaking it in heated oil.
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.
SEM008A
SEM931C
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)
SEM932C
SEM008A

CYLINDER HEADEM-71
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Revision: November 2009 2006 QX56
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 using suitable tool.
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.
KBIA2530E
Valve guide hole diameter:
Intake and exhaust : 6.000 - 6.018 mm (0.2362 - 0.2369 in)
SEM932C
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)
SEM795A

CYLINDER BLOCKEM-87
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Revision: November 2009 2006 QX56

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

Face the chamfered or rounded edge side to the crankshaft.
How to Select Piston and Bearing EBS00RFJ
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.
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.
KBIA2537E
Connecting pointsConnecting parts Selection itemsSelection methods
Between cylinder block to
crankshaft Main bearing
Main 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 rod Connecting rod bearing
Connecting 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-
ton Piston 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 ———
KBIA2495E

EM-88Revision: November 2009
CYLINDER BLOCK
2006 QX56
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 the 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.
HOW TO SELECT CONNECTING ROD BEARING
When New Connecting Rod and Crankshaft are Used
1. Apply the big end inside diameter grade stamped on the con- necting rod side face to the row in the “Connecting Rod Bearing
Selection Table ”.
KBIA2496E
Grade number (Mark) 123
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)
KBIA2536E

EM-90Revision: November 2009
CYLINDER BLOCK
2006 QX56
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.
When Cylinder Block and Crankshaft are Reused
1. Measure the inside diameter of the cylinder block main bearings housing and the outside diameter of thecrankshaft journal.
2. Apply measurement in above step 1 to "Main Bearings Selection Table".
3. The following steps are same as in “When New Cylinder Block and Crankshaft are Used”. Refer to EM-90,
"HOW TO SELECT MAIN BEARING" .
UndersizeThickness
0.25 (0.0098) 1.627 - 1.635 (0.0641 - 0.0644)
Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)
PBIC0111E
KBIA2495E
PBIC0110E

CYLINDER BLOCKEM-95
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Revision: November 2009 2006 QX56
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-87, "
HOW TO SELECT PISTON" .

Refer to the connecting rod bearing selection table to replace
connecting rod. Refer to EM-88, "
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-96, "CONNECTING ROD BUSHING OIL CLEAR-
ANCE (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-99, "
Piston to Cylinder Bore Clearance" .

Insert the piston ring into the middle of the cylinder using the pis-
ton, and measure the 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)
SEM024AA
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)
PBIC0118E