2006 INFINITI QX56 engine coolant

ATC-180
REFRIGERANT LINES
Revision: November 20092006 QX56
CAUTION:

Replace the O-ring of the high-pressure pipe with a new one, then apply compressor oil to it when
installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Low-pressure PipeEJS003YY
REMOVAL
1. Discharge the refrigerant. Refer to ATC-171, "HFC-134a (R-134a) Service Procedure" .
2. Remove the cowl top and the cowl top extension. Refer to EI-18, "
COWL TOP" .
3. Remove the low-pressure pipe. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-173, "
Components" .
CAUTION:

Replace the O-ring of the high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Rear High- and Low-pressure A/C and Heater Core
Pipes
EJS005Y8
REMOVAL
1. Discharge the refrigerant. Refer to ATC-171, "HFC-134a (R-134a) Service Procedure" .
2. Drain the coolant from the engine cooling system. Refer to CO-10, "
Changing Engine Coolant" .
3. Disconnect the underfloor rear heater hoses (1 and 2) from the rear heater pipes underneath the vehicle.

⇐: Front
4. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the under-
floor rear high- and low-pressure pipes underneath the vehicle.
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
5. Remove the rear high- and low-pressure pipes nuts (B) under- neath the vehicle.
NOTE:
The remaining steps are performed inside the rear luggage area of the vehicle.
6. Remove the luggage side finisher lower RH. Refer to EI-40, "
LUGGAGE FLOOR TRIM" .
7. Disconnect the rear heater core hoses (1 and 2) from the rear heater core (3).

⇐: Front
WJIA2310E
WJIA2311E

REFRIGERANT LINESATC-181
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Revision: November 2009 2006 QX56
8. Remove the rear high- and low-pressure pipes bracket bolt (A)
to release the bracket.

Rear blower motor (1)

⇐: Front
9. Remove the rear high- and low-pressure pipes bolt (A) to dis- connect the rear high- and low-pressure pipes from the rear
expansion valve (1).

⇐: Front
CAUTION:
Cap or wrap the joint of the pipes with suitable material
such as vinyl tape to avoid the entry of air.
10. Disconnect the following electrical connectors:

Rear air mix door motor (1)

Rear blower motor resistor (2)

Rear blower motor (3)

⇐ : Front
11. Disconnect the ducts from the rear heater and cooling unit assembly. Refer to ATC-166, "
Components" .
12. Remove the rear heater and cooling unit assembly. CAUTION:
Cap or wrap the joint of the pipes with suitable material such as vinyl tape to avoid the entry of air.
13. Remove the rear high- and low-pressure A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-173, "
Components" .
CAUTION:

Replace the O-ring of the high/low-pressure pipe with a new one, then apply compressor oil to it
when installing it.

After charging refrigerant, check for leaks.
Removal and Installation for Underfloor Rear High- and Low-pressure A/C and
Heater Core Pipes
EJS005Y9
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-10, "Changing Engine Coolant" .
2. Disconnect the battery negative terminal.
3. Disconnect the generator harness.
4. Discharge the refrigerant. Refer to ATC-171, "
HFC-134a (R-134a) Service Procedure" .
WJIA2312E
WJIA2313E
WJIA2314E

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION
A
CO
Revision: November 2009 2006 QX56
PRECAUTIONS .....................................................
..... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 2
Precautions for Liquid Gasket ............................. ..... 2
REMOVAL OF LIQUID GASKET SEALING ..... ..... 2
LIQUID GASKET APPLICATION PROCEDURE ..... 2
PREPARATION ...................................................... ..... 4
Special Service Tools .......................................... ..... 4
Commercial Service Tools ................................... ..... 4
OVERHEATING CAUSE ANALYSIS ..................... ..... 6
Troubleshooting Chart ......................................... ..... 6
COOLING SYSTEM ............................................... ..... 8
Cooling Circuit .......................................................... 8
System Drawing ....................................................... 9
ENGINE COOLANT ............................................... ... 10
Inspection ............................................................ ... 10
LEVEL CHECK ................................................ ... 10
CHECKING COOLING SYSTEM FOR LEAKS ... 10
CHECKING RESERVOIR CAP ........................ ... 10
CHECKING RADIATOR CAP ........................... ... 10
Changing Engine Coolant ................................... ... 10
DRAINING ENGINE COOLANT ...................... .... 11
REFILLING ENGINE COOLANT ..................... .... 11
FLUSHING COOLING SYSTEM ...................... ... 12
RADIATOR ............................................................. ... 14
Removal and Installation ..................................... ... 14
REMOVAL ........................................................ ... 14
INSTALLATION ................................................ ... 16INSPECTION AFTER INSTALLATION .............
... 16
Checking Radiator ............................................... ... 16
ENGINE COOLING FAN ........................................ ... 17
Removal and Installation (Crankshaft Driven Type) ... 17
REMOVAL ........................................................ ... 17
INSPECTION AFTER REMOVAL .................... ... 17
INSTALLATION ................................................ ... 17
INSPECTION AFTER INSTALLATION ............. ... 17
Removal and Installation (Motor Driven Type) .... ... 18
REMOVAL ........................................................ ... 18
INSTALLATION ................................................ ... 18
WATER PUMP ....................................................... ... 19
Removal and Installation ..................................... ... 19
REMOVAL ........................................................ ... 19
INSPECTION AFTER REMOVAL .................... ... 19
INSTALLATION ................................................ ... 19
INSPECTION AFTER INSTALLATION ............. ... 20
THERMOSTAT AND WATER PIPING ................... ... 21
Removal and Installation ..................................... ... 21
REMOVAL ........................................................ ... 21
INSPECTION AFTER REMOVAL .................... ... 22
INSTALLATION ................................................ ... 22
INSPECTION AFTER INSTALLATION ............. ... 22
SERVICE DATA AND SPECIFICATIONS (SDS) ... ... 23
Standard and Limit ............................................... ... 23
ENGINE COOLANT CAPACITY (APPROXI-
MATE) ............................................................... ... 23
THERMOSTAT ................................................. ... 23
RADIATOR ....................................................... ... 23

PRECAUTIONSCO-3
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3. Attach the liquid gasket tube to the Tool.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants" .
4. Apply the liquid gasket without breaks to the specified location with the specified dimensions.

If there is a groove for the liquid gasket application, apply the
liquid gasket to the groove.

As for the bolt holes, normally apply the liquid gasket inside
the holes. If specified in the procedure, it should also be
applied outside the holes.

Within five minutes of liquid gasket application, install the mat-
ing component.

If the liquid gasket protrudes, wipe it off immediately.

Do not retighten after the installation.

Wait 30 minutes or more after installation before refilling the
engine with engine oil and engine coolant.
CAUTION:
If there are specific instructions in this manual, observe them. Tool number : WS39930000 ( — )
WBIA0567E
SEM159F

CO-4Revision: November 2009
PREPARATION
2006 QX56
PREPARATIONPFP:00002
Special Service ToolsEBS00RE4
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00RE5
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10111100
(J-37228)
Seal cutter Removing steel oil pan and rear timing chain
case
WS39930000
( — )
Tube pressure Pressing the tube of liquid gasket
EG17650301
(J-33984-A)
Radiator cap tester adapter Adapting radiator cap tester to radiator cap
and radiator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV991J0070
(J-45695)
Coolant refill tool For refilling engine cooling system
KV991J0010
(J-23688)
Engine coolant refractometer Checking concentration of ethylene glycol in
engine coolant
NT046
S-NT052
S-NT564
LMA053
WBIA0539E

CO-6Revision: November 2009
OVERHEATING CAUSE ANALYSIS
2006 QX56
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartEBS00RE6
SymptomCheck items
Cooling sys-
tem parts
malfunction Poor heat transfer
Water pump malfunction Worn or loose drive belt
—
Thermostat stuck closed
—
Damaged fins Dust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tube Excess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunction Excess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flow Cooling fan does not oper-
ate
Fan assembly —
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud —— —
Improper engine coolant
mixture ratio —— —
Poor engine coolant quality —Engine coolant density —
Insufficient engine coolant Engine coolant leaks Cooling hose
Loose clamp
Cracked hose
Water pump Poor sealing
Radiator cap Loose
Poor sealing
Radiator O-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tank Exhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

CO-10Revision: November 2009
ENGINE COOLANT
2006 QX56
ENGINE COOLANTPFP:KQ100
InspectionEBS00RE9
LEVEL CHECK

Check if the engine coolant reservoir tank level is within MIN to
MAX level when engine is cool.

Adjust engine coolant level as necessary.
CHECKING COOLING SYSTEM FOR LEAKS
WARNING:
Never remove the radiator or reservoir cap when the engine is hot. Serious burns could occur from
high-pressure engine coolant escaping from the radiator or reservoir.

To check for leakage, apply pressure to the cooling system at
the reservoir filler neck using suitable tool and Tool.
CAUTION:
Higher pressure than specified may cause radiator damage.
NOTE:
In case that engine coolant decreases, replenish cooling system
with engine coolant.

If any concerns are found, repair or replace damaged parts.
CHECKING RESERVOIR CAP

Check reservoir cap relief pressure using suitable tool and Tool.
NOTE:
Apply engine coolant to the cap seal.

Replace the reservoir cap if there is any damage in the nega-
tive-pressure valve, or if the open-valve pressure is outside of
the limit.
CHECKING RADIATOR CAP
Inspect the radiator cap.
NOTE:
Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.

Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the
metal retainer.
Changing Engine CoolantEBS00REA
WARNING:

To avoid being scalded, never change the coolant when the engine is hot.

Wrap a thick cloth around the cap to carefully remove the cap. First, turn the cap a quarter of a
turn to release any built-up pressure, then push down and turn the cap all the way to remove it.
SMA412B
Tool number : EG17650301 (J-33984-A)
Leakage test pressure : 137 kPa (1.4 kg/cm, 20 psi)
WBIA0612E
Tool number : EG17650301 (J-33984-A)
Standard: 95 - 125 kPa (0.97 - 1.28 kg/cm
2 , 14 - 18 psi)
WBIA0611E

ENGINE COOLANTCO-11
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DRAINING ENGINE COOLANT
1. Turn ignition switch ON and set temperature control lever all the way to HOT position or the highest tem-
perature position. Wait 10 seconds and turn ignition switch OFF.
2. Remove the engine front undercover using power tool.
3. Open the radiator drain plug at the bottom of the radiator, and remove the radiator filler cap. This is the only step required
when partially draining the cooling system (radiator only).
CAUTION:
Do not to allow the coolant to contact the drive belts.
4. When draining all of the coolant in the system for engine removal or repair, it is necessary to drain the cylinder block.
Remove the RH cylinder block drain plug to drain the right bank
and the oil cooler hose to drain the left bank as shown.
5. Remove the reservoir tank to drain the engine coolant, then clean the reservoir tank before installing it.
6. Check the drained coolant for contaminants such as rust, corrosion or discoloration. If the coolant is contaminated, flush the engine cooling system. Refer to CO-12, "
FLUSHING COOLING
SYSTEM" .
REFILLING ENGINE COOLANT
1. Close the radiator drain plug. Install the reservoir tank, cylinder block drain plug, and the oil cooler hose, if
removed for a total system drain or for engine removal or repair.

The radiator must be completely empty of coolant and water.

Apply sealant to the threads of the cylinder block drain plug. Use Genuine High Performance Thread
Sealant or equivalent. Refer to GI-46, "
Recommended Chemical Products and Sealants" .
2. Set the vehicle heater controls to the full HOT and heater ON position. Turn the vehicle ignition ON with the engine OFF as necessary to activate the heater mode.
3. Remove the vented reservoir cap and replace it with a non-vented reservoir cap before filling the cooling system.
WBIA0391E
PBIC0146E
WBIA0392E
Radiator drain plug : Refer to CO-14, "RADIATOR" .
RH cylinder block drain plug : Refer to EM-78, "
CYLINDER BLOCK" .