2006 INFINITI FX35 engine cooling

HEATER & COOLING UNIT ASSEMBLY ATC-125
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Revision: 2006 December 2006 FX35/FX45
HEATER & COOLING UNIT ASSEMBLYPFP:27110
Removal and InstallationNJS000EU
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Drain coolant from cooling system. Refer to CO-11, "
Changing Engine Coolant" (VQ35DE) or CO-38,
"Changing Engine Coolant" (VK45DE).
3. Remove cowl top cover. Refer to EI-23, "
COWL TOP" .
4. Remove high-pressure pipe 2 mounting clip.
5. Remove low-pressure flexible hose bracket mounting bolt. Refer to ATC-146, "
Removal and Installation of
Low-pressure Flexible Hose" .
6. Disconnect low-pressure pipe 1 and high-pressure pipe 2 from evaporator.
a. Set a disconnector [high-pressure side (SST: 9253089908), low- pressure side (SST: 9253089916)] on A/C piping.
b. Slide a disconnector toward vehicle front until it clicks.
c. Slide A/C piping toward vehicle front and disconnect it.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
7. Remove electric throttle control actuator (VQ35DE). Refer to EM-19, "
INTAKE MANIFOLD COLLECTOR" .
8. Disconnect two heater hoses from heater core.
9. Remove instrument panel assembly. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
10. Remove blower unit. Refer to ATC-120, "
BLOWER UNIT" .
RJIA2037E
RJIA2041E
RJIA2077E

HEATER & COOLING UNIT ASSEMBLY ATC-127
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Revision: 2006 December 2006 FX35/FX45

Insert piping securely until a click is heard.

After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.

When recharging refrigerant, check for leaks.
NOTE:

When filling radiator with coolant, refer to CO-11, "Changing Engine Coolant" (VQ35DE) or CO-38,
"Changing Engine Coolant" (VK45DE).

Recharge the refrigerant.
Heater & cooling unit assembly mounting bolt : 6.8 N·m (0.69 kg-m, 60 in-lb)
Steering member mounting nut and bolt : 12 N·m (1.2 kg-m, 9 fl-lb)
Steering column mounting nut and bolt : 16.7 N·m (1.7 kg-m, 12 fl-lb)

REFRIGERANT LINES ATC-141
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Revision: 2006 December 2006 FX35/FX45
VK45DE
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove air cleaner case and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" (VQ35DE) or
EM-177, "
AIR CLEANER AND AIR DUCT" (VK45DE).
3. Remove front engine undercover, using power tools.
4. Remove cooling fan shroud (lower). Refer to CO-41, "
RADIATOR" (VK45DE).
5. Remove mounting nuts from low-pressure flexible hose and high-pressure flexible hose.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
6. Remove high-pressure flexible hose. Refer to ATC-147,
"Removal and Installation of High-pressure Flexible Hose"
(VK45DE).
7. Disconnect compressor connector.
8. Remove A/C compressor belt. Refer to EM-15, "
DRIVE BELTS" (VQ35DE) or EM-174, "DRIVE BELTS"
(VK45DE).
RJIA2244E
RJIA2059E
RJIA2058E

ATC-158
REFRIGERANT LINES
Revision: 2006 December 2006 FX35/FX45
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Stop engine.
2. Connect a suitable A/C manifold gauge set (SST: J-39183) to the A/C service valves.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above 16 °C (61 °F). If less
than specification, recover/evacuate and recharge the system with the specified amount of refrigerant.
NOTE:
At temperatures below 16 °C (61 °F), leaks may not be detected since the system may not reach 345 kPa
(3.52 kg/cm
2 , 50 psi).
4. Perform the leak test from the high-pressure side (compressor discharge a to evaporator inlet h) to the low-pressure side [evaporator drain hose i to shaft seal o (VK45DE) or n (VQ35DE)]. Refer to ATC-139,
"Components" . Perform a leak check for the following areas carefully. Clean the component to be
checked and move the leak detected probe completely around the connection/component.
Compressor
Check the fitting of high- and low-pressure flexible hoses, relief valve and shaft seal.
Condenser
Check the fitting of high-pressure flexible hose and pipe, refrigerant pressure sensor.
Liquid tank
Check the fitting of refrigerant connection.
Service valves
Check all around the service valves. Ensure service valve caps are secured on the service valves (to pre-
vent leaks).
NOTE:
After removing A/C manifold gauge set from service valves, wipe any residue from valves to prevent any
false readings by leak detector.
Cooling unit (Evaporator)
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in the
cooling unit. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer’s recommended
procedure for actual wait time) before inserting the leak detector probe into the drain hose.
Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak detector detects a leak, verify at least once by blowing compressed air into area of suspected leak, then repeat check as outlined above.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components. If no leaks are found, perform steps 7 - 10.
7. Start the engine.
8. Set the A/C control as follows;
a. A/C switch: ON
b. Mode door position: VENT (Ventilation)
c. Intake position: Recirculation
d. Temperature setting: Max. cold
e. Fan speed: High
9. Run engine at 1,500 rpm for at least 2 minutes.
10. Stop the engine and perform leak check again following steps 4 through 6 above.
Refrigerant leaks should be checked immediately after stopping
the engine. Begin with the leak detector at the compressor. The
pressure on the high-pressure side will gradually drop after
refrigerant circulation stops and pressure on the low-pressure
side will gradually rise, as shown in the graph. Some leaks are
more easily detected when pressure is high.
SHA839E

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
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CO
Revision: 2006 December 2006 FX35/FX45
ENGINE COOLING SYSTEM
VQ35DE
PRECAUTIONS ..................................................... ..... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 3
Precautions for Liquid Gasket ............................. ..... 3
REMOVAL OF LIQUID GASKET SEALING ..... ..... 3
LIQUID GASKET APPLICATION PROCEDURE ..... 3
PREPARATION ...................................................... ..... 5
Special Service Tools .......................................... ..... 5
Commercial Service Tools ................................... ..... 6
OVERHEATING CAUSE ANALYSIS ..................... ..... 7
Troubleshooting Chart ......................................... ..... 7
COOLING SYSTEM ............................................... ..... 9
Cooling Circuit ..................................................... ..... 9
System Chart ...................................................... ... 10
ENGINE COOLANT ............................................... ....11
Inspection ............................................................ .... 11
LEVEL CHECK ................................................ .... 11
LEAK CHECK .................................................. .... 11
Changing Engine Coolant ................................... .... 11
DRAINING ENGINE COOLANT ...................... .... 11
REFILLING ENGINE COOLANT ..................... ... 12
FLUSHING COOLING SYSTEM ...................... ... 13
RADIATOR ............................................................. ... 14
Components ........................................................ ... 14
Removal and Installation ..................................... ... 14
REMOVAL ........................................................ ... 14
INSTALLATION ................................................ ... 15
INSPECTION AFTER INSTALLATION ............ ... 15
Checking Radiator Cap ....................................... ... 15
Checking Radiator ............................................... ... 16
RADIATOR (ALUMINUM TYPE) ........................... ... 17
Components ........................................................ ... 17
Disassembly and Assembly ................................ ... 17
PREPARATION ................................................ ... 17
DISASSEMBLY ................................................ ... 17
ASSEMBLY ...................................................... ... 18
INSPECTION ................................................... ... 20 COOLING FAN .......................................................
... 21
Components ........................................................ ... 21
Removal and Installation ..................................... ... 21
REMOVAL ........................................................ ... 21
INSTALLATION ................................................ ... 21
INSPECTION AFTER INSTALLATION ............. ... 21
Disassembly and Assembly ................................. ... 21
DISASSEMBLY ................................................ ... 21
INSPECTION AFTER DISASSEMBLY ............. ... 21
ASSEMBLY ...................................................... ... 21
WATER PUMP ....................................................... ... 22
Components ........................................................ ... 22
Removal and Installation ..................................... ... 22
REMOVAL ........................................................ ... 22
INSPECTION AFTER REMOVAL .................... ... 24
INSTALLATION ................................................ ... 24
INSPECTION AFTER INSTALLATION ............. ... 26
WATER INLET AND THERMOSTAT ASSEMBLY . ... 27
Components ........................................................ ... 27
Removal and Installation ..................................... ... 27
REMOVAL ........................................................ ... 27
INSPECTION AFTER REMOVAL .................... ... 28
INSTALLATION ................................................ ... 28
INSPECTION AFTER INSTALLATION ............. ... 28
WATER OUTLET AND WATER PIPING ................ ... 29
Components ........................................................ ... 29
Removal and Installation ..................................... ... 29
REMOVAL ........................................................ ... 29
INSTALLATION ................................................ ... 30
INSPECTION AFTER INSTALLATION ............. ... 30
SERVICE DATA AND SPECIFICATIONS (SDS) ... ... 31
Standard and Limit ............................................... ... 31
ENGINE COOLANT CAPACITY (APPROXI-
MATE) ............................................................... ... 31
RADIATOR ....................................................... ... 31
THERMOSTAT ................................................. ... 31

CO-2Revision: 2006 December 2006 FX35/FX45
VK45DE
PRECAUTIONS ...................................................... ... 32
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .............................................................. ... 32
PREPARATION ...................................................... ... 33
Special Service Tools .......................................... ... 33
Commercial Service Tools ................................... ... 33
OVERHEATING CAUSE ANALYSIS ..................... ... 34
Troubleshooting Chart ......................................... ... 34
COOLING SYSTEM ............................................... ... 36
Cooling Circuit ..................................................... ... 36
System Chart ....................................................... ... 37
ENGINE COOLANT ............................................... ... 38
Inspection ............................................................ ... 38
LEVEL CHECK ................................................. ... 38
LEAK CHECK ................................................... ... 38
Changing Engine Coolant .................................... ... 38
DRAINING ENGINE COOLANT ....................... ... 38
REFILLING ENGINE COOLANT ...................... ... 39
FLUSHING COOLING SYSTEM ...................... ... 40
RADIATOR ............................................................. ... 41
Components ........................................................ ... 41
Removal and Installation ..................................... ... 41
REMOVAL ........................................................ ... 41
INSTALLATION ................................................. ... 43
INSPECTION AFTER INSTALLATION ............. ... 43
Checking Radiator Cap ....................................... ... 43
Checking Radiator ............................................... ... 44
RADIATOR (ALUMINUM TYPE) ............................ ... 45
Components ........................................................ ... 45
Disassembly and Assembly ................................. ... 45
PREPARATION ................................................ ... 45
DISASSEMBLY ................................................ ... 45
ASSEMBLY ...................................................... ... 46
INSPECTION .................................................... ... 48 COOLING FAN .......................................................
... 49
Components (Crankshaft Driven type) ................. ... 49
Removal and Installation ...................................... ... 49
REMOVAL ......................................................... ... 49
INSPECTION AFTER REMOVAL ..................... ... 49
INSTALLATION ................................................. ... 49
Components (Motor Driven Type) ........................ ... 50
Removal and Installation ...................................... ... 50
REMOVAL ......................................................... ... 50
INSTALLATION ................................................. ... 50
Disassembly and Assembly (Motor Driven Type) ... 50 DISASSEMBLY ................................................. ... 50
INSPECTION AFTER DISASSEMBLY ............. ... 50
ASSEMBLY ....................................................... ... 50
WATER PUMP ........................................................ ... 51
Components ......................................................... ... 51
Removal and Installation ...................................... ... 51
REMOVAL ......................................................... ... 51
INSPECTION AFTER REMOVAL ..................... ... 52
INSTALLATION ................................................. ... 52
INSPECTION AFTER INSTALLATION ............. ... 52
THERMOSTAT AND WATER CONTROL VALVE .. ... 53
Components ......................................................... ... 53
Removal and Installation ...................................... ... 54
REMOVAL ......................................................... ... 54
INSPECTION AFTER REMOVAL ..................... ... 54
INSTALLATION ................................................. ... 54
INSPECTION AFTER INSTALLATION ............. ... 55
SERVICE DATA AND SPECIFICATIONS (SDS) ... ... 56
Standard and Limit ............................................... ... 56
ENGINE COOLANT CAPACITY (APPROXI-
MATE) ............................................................... ... 56
RADIATOR ........................................................ ... 56
THERMOSTAT .................................................. ... 56
WATER CONTROL VALVE ............................... ... 56

OVERHEATING CAUSE ANALYSIS CO-7
[VQ35DE]
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Revision: 2006 December 2006 FX35/FX45
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartNBS003JR
Symptom Check 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.)
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 system Cylinder head deterioration
Cylinder head gasket dete-
rioration

ENGINE COOLANT CO-11
[VQ35DE]
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Revision: 2006 December 2006 FX35/FX45
ENGINE COOLANTPFP:KQ100
InspectionNBS003JU
LEVEL CHECK

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

Adjust the engine coolant level as necessary.
LEAK CHECK

To check for leaks, apply pressure to the cooling system with the
radiator cap tester (commercial service tool) and radiator cap
tester adapter (SST).
WARNING:
Do not remove radiator cap when engine is hot. Serious
burns could occur from high-pressure engine coolant
escaping from radiator.
CAUTION:
Higher test pressure than specified may cause radiator
damage.
NOTE:
In a case that engine coolant decreases, replenish radiator with engine coolant.

If anything is found, repair or replace damaged parts.
Changing Engine CoolantNBS003JV
WARNING:

To avoid being scalded, do not change engine coolant when the engine is hot.

Wrap a thick cloth around radiator cap and carefully remove radiator cap. First, turn radiator cap a
quarter of a turn to release built-up pressure. Then turn radiator cap all the way.
DRAINING ENGINE COOLANT
1. Remove front engine undercover with power tool.
2. Open radiator drain plug at the bottom of radiator, and then remove radiator cap.
When draining all of engine coolant in the system, open water drain plugs on cylinder block. Refer
to EM-124, "
DISASSEMBLY" .
3. Remove reservoir tank as necessary, and drain engine coolant and clean reservoir tank before installing.
SMA412B
Testing pressure : 157 kPa (1.6 kg/cm
2 , 23 psi)
SLC756A
SBIA0444E