2005 INFINITI QX4 engine coolant

HEATER & COOLING UNIT ASSEMBLY
ATC-159
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AT C
Revision: October 20052005 QX56
3. Disconnect the rear heater core pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-156, "
Components" .
NOTE:

Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "REFILLING ENGINE
COOLANT"

ATC-162
HEATER CORE
Revision: October 20052005 QX56
5. Remove the heater core.
NOTE:
If the in-cabin microfilters are contaminated from coolant leaking
from the heater core, replace the in-cabin microfilters with new
ones before installing the new heater core.
Installation
Installation is in the reverse order of removal.
REAR HEATER CORE
Removal
1. Partially drain the engine cooling system. Refer to MA-13, "DRAINING ENGINE COOLANT" .
2. Remove the rear RH interior trim panel. Refer to EI-35, "
BODY SIDE TRIM" .
3. Disconnect the rear heater hoses from the heater core.
4. Remove the rear heater core bracket.
5. Remove the heater core.
Installation
Installation is in the reverse order of removal.
LJIA0134E
LJIA0069E
LJIA0071E

ATC-184
REFRIGERANT LINES
Revision: October 20052005 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-175, "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-177, "
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 A/C PipesEJS00537
REMOVAL
1. Drain the coolant from the engine cooling system. Refer to CO-10, "DRAINING ENGINE COOLANT" .
2. Diconnect the negative battery terminal.
3. Discharge the refrigerant from the A/C system. Refer to ATC-175, "
HFC-134a (R-134a) Service Proce-
dure" .
4. Disconnect the chassis harness connector.
5. Set four suitable jacks at the body mounting points to support the vehicle body when it is seperated from
the frame.
6. Remove the RH body mount bolts. Refer to BL-159, "
Body Mounting"
7. Use the vehicle hoist to lower the frame from the body until there is sufficient clearance for the underfloor
rear high- and low-pressure A/C and heater core pipes from the body.
8. Remove the underfloor rear high- and low-pressure A/C and heater core pipes .
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-177, "
Components" .
CAUTION:

Replace the O-rings of the high-pressure pipe and the high-pressure flexible hose with new ones,
then apply compressor oil to them after installing them.

After charging refrigerant, check for leaks.
Removal and Installation for Rear A/C PipesEJS00538
REMOVAL
1. Discharge the refrigerant from the A/C system. Refer to ATC-175, "HFC-134a (R-134a) Service Proce-
dure"
2. Remove the upper and lower luggage RH side finisher lower. Refer to EI-35, "BODY SIDE TRIM"
3. Disconnect the rear A/C pipes.
INSTALLATION
Installation is in the reverse order of removal.
Refer to ATC-177, "
Components" .
CAUTION:

Replace the O-rings of the high-pressure pipe and the high-pressure flexible hose with new ones,
then apply compressor oil to them after installing them.

After charging refrigerant, check for leaks.

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
A
CO
Revision: October 20052005 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 ......................... 10
REFILLING ENGINE COOLANT .........................11
FLUSHING COOLING SYSTEM ..........................11
RADIATOR ................................................................ 12
Removal and Installation ........................................ 12
REMOVAL ........................................................... 12
INSTALLATION ................................................... 14INSPECTION AFTER INSTALLATION ................ 14
Checking Radiator .................................................. 14
ENGINE COOLING FAN ........................................... 15
Removal and Installation (Crankshaft Driven Type) ... 15
REMOVAL ........................................................... 15
INSPECTION AFTER REMOVAL ....................... 15
INSTALLATION ................................................... 15
INSPECTION AFTER INSTALLATION ................ 15
Removal and Installation (Motor Driven Type) ....... 16
REMOVAL ........................................................... 16
INSTALLATION ................................................... 16
WATER PUMP .......................................................... 17
Removal and Installation ........................................ 17
REMOVAL ........................................................... 17
INSPECTION AFTER REMOVAL ....................... 17
INSTALLATION ................................................... 17
INSPECTION AFTER INSTALLATION ................ 18
THERMOSTAT AND WATER PIPING ...................... 19
Removal and Installation ........................................ 19
REMOVAL ........................................................... 19
INSPECTION AFTER REMOVAL ....................... 20
INSTALLATION ................................................... 20
INSPECTION AFTER INSTALLATION ................ 20
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 21
Standard and Limit .................................................. 21
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 21
THERMOSTAT .................................................... 21
RADIATOR .......................................................... 21

PRECAUTIONS
CO-3
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Revision: October 20052005 QX56
3. Attach the liquid gasket tube to the Tool.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
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
SEM 15 9F

CO-4Revision: October 2005
PREPARATION
2005 QX56
PREPARATIONPFP:00002
Special Service ToolsEBS00LN0
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00LN1
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10111100
(J-37228)
Seal cutterRemoving steel oil pan and rear timing chain
case
WS39930000
(—)
Tube pressurePressing the tube of liquid gasket
EG17650301
(J-33984-A)
Radiator cap tester adapterAdapting 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)
—
(J-23688)
Engine coolant refractometerChecking concentration of ethylene glycol in
engine coolant
NT046
S-NT052
S-NT564
W BIA0539E
Tool nameDescription
Power toolLoosening bolts and nuts
Radiator cap tester Checking radiator and radiator cap
PBIC0190E
PBIC1982E

CO-6Revision: October 2005
OVERHEATING CAUSE ANALYSIS
2005 QX56
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartEBS00LN2
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunctionExcess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flowCooling 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 coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

CO-10Revision: October 2005
ENGINE COOLANT
2005 QX56
ENGINE COOLANTPFP:KQ100
InspectionEBS00LN5
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
WAR NIN G:
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 CoolantEBS00LN6
Refer to MA-13, "Changing Engine Coolant" .
DRAINING ENGINE COOLANT
Refer to MA-13, "DRAINING ENGINE COOLANT" .
SM A41 2B
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