engine cooling INFINITI M35 2006 Factory User Guide

HEATER & COOLING UNIT ASSEMBLY
ATC-137
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Revision: 2006 January2006 M35/M45
CAUTION:
Replace O-rings of A/C piping with new ones, and then apply compressor oil to it when installing
it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
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-40,
"Changing Engine Coolant" (VK45DE).
Recharge the refrigerant.
Heater & cooling unit assembly mounting bolt
: 6.9 Nꞏm (0.7 kg-m, 61 in-lb)
Instrument stay mounting nut and bolt
: 12 Nꞏm (1.25 kg-m, 9 ft-lb)

REFRIGERANT LINES
ATC-165
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INSTALLATION
Install liquid tank, and then install liquid tank bracket on condenser.
CAUTION:
Make sure liquid tank bracket is securely installed at protru-
sion of condenser. (Make sure liquid tank bracket does not
move to a position below center of liquid tank.)
Replace O-rings of A/C piping with new ones, and then
apply compressor oil to it when installing it.
When recharging refrigerant, check for leaks.
Removal and Installation of CondenserNJS000HU
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove engine cover. Refer to EM-14, "
ENGINE ROOM COVER" (VQ35DE) or EM-173, "ENGINE
ROOM COVER" (VK45DE).
3. Remove air cleaner case, air hose and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT"
(VQ35DE) or EM-177, "AIR CLEANER AND AIR DUCT" (VK45DE).
4. Remove engine under cover, using power tools.
5. Drain engine coolant. Refer to CO-11, "
Changing Engine Coolant" (VQ35DE) or CO-40, "Changing
Engine Coolant" (VK45DE).
6. Remove radiator fan shroud with cooling fan after (VK45DE). Refer to CO-51, "
COOLING FAN" .
7. Remove mounting clips and bolts, and then remove bracket.
8. Remove radiator upper mount, remove radiator and condenser
to the engine side.
9. Remove mounting bolt from high-pressure flexible hose bracket.
10. Remove high-pressure pipe1 from vehicle clip.
RJIA1441E
RJIA4173E
RJIA4174E

ATC-172
REFRIGERANT LINES
Revision: 2006 January2006 M35/M45
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 16C (61F). If less
than specification, recover/evacuate and recharge the system with the specified amount of refrigerant.
NOTE:
At temperatures below 16
C (61F), 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 m(VQ35DE) or n(VK45DE)]. Refer to ATC-153,
"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.
Liquid tank
Check the fitting of refrigerant pressure sensor.
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 door 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.
11. Before connecting recovery/recycling recharging equipment to
vehicle, check recovery/recycling recharging equipment gauges.
SHA839E

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
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Revision: 2006 January2006 M35/M45
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 ................................................... 16
INSPECTION AFTER INSTALLATION ............... 16
Checking Radiator Cap .......................................... 16
Checking Radiator .................................................. 16
RADIATOR (ALUMINUM TYPE) .............................. 18
Components ........................................................... 18
Disassembly and Assembly ................................... 18
PREPARATION ................................................... 18
DISASSEMBLY ................................................... 18
ASSEMBLY ......................................................... 19
INSPECTION ...................................................... 21COOLING FAN .......................................................... 22
Components ........................................................... 22
Removal and Installation ........................................ 22
REMOVAL ........................................................
... 22
INSTALLATION ................................................... 22
INSPECTION AFTER INSTALLATION ................ 22
Disassembly and Assembly .................................... 23
DISASSEMBLY ................................................... 23
INSPECTION AFTER DISASSEMBLY ................ 23
ASSEMBLY ......................................................... 23
WATER PUMP .......................................................... 24
Components ........................................................... 24
Removal and Installation ........................................ 24
REMOVAL ........................................................
... 24
INSPECTION AFTER REMOVAL ....................... 26
INSTALLATION ................................................... 26
INSPECTION AFTER INSTALLATION ................ 28
WATER INLET AND THERMOSTAT ASSEMBLY .... 29
Components ........................................................... 29
Removal and Installation ........................................ 29
REMOVAL ........................................................
... 29
INSPECTION AFTER REMOVAL ....................... 30
INSTALLATION ................................................... 30
INSPECTION AFTER INSTALLATION ................ 30
WATER OUTLET AND WATER PIPING ................... 31
Components ........................................................... 31
Removal and Installation ........................................ 31
REMOVAL ........................................................
... 31
INSTALLATION ................................................... 32
INSPECTION AFTER INSTALLATION ................ 32
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 33
Standard and Limit .................................................. 33
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 33
RADIATOR .......................................................
... 33
THERMOSTAT .................................................... 33

CO-2Revision: 2006 January2006 M35/M45
VK45DE
PRECAUTIONS ......................................................... 34
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................. 34
PREPARATION ......................................................... 35
Special Service Tools ............................................. 35
Commercial Service Tools ...................................... 35
OVERHEATING CAUSE ANALYSIS ........................ 36
Troubleshooting Chart ............................................ 36
COOLING SYSTEM .................................................. 38
Cooling Circuit ........................................................ 38
System Chart .......................................................... 39
ENGINE COOLANT .................................................. 40
Inspection ............................................................... 40
LEVEL CHECK .................................................... 40
LEAK CHECK ...................................................... 40
Changing Engine Coolant ....................................... 40
DRAINING ENGINE COOLANT .......................... 40
REFILLING ENGINE COOLANT ......................... 41
FLUSHING COOLING SYSTEM ......................... 42
RADIATOR ................................................................ 43
Components ........................................................... 43
Removal and Installation ........................................ 43
REMOVAL ........................................................
... 43
INSTALLATION .................................................... 45
INSPECTION AFTER INSTALLATION ................ 45
Checking Radiator Cap .......................................... 45
Checking Radiator .................................................. 45
RADIATOR (ALUMINUM TYPE) ............................... 47
Components ........................................................... 47
Disassembly and Assembly .................................... 47
PREPARATION ................................................... 47
DISASSEMBLY ................................................... 47
ASSEMBLY ......................................................... 48
INSPECTION ....................................................... 50COOLING FAN .......................................................... 51
Components ............................................................ 51
Removal and Installation ......................................... 51
REMOVAL ............................................................ 51
INSTALLATION .................................................... 51
INSPECTION AFTER INSTALLATION ................ 51
Disassembly and Assembly .................................... 52
DISASSEMBLY .................................................... 52
INSPECTION AFTER DISASSEMBLY ................ 52
ASSEMBLY .......................................................... 52
WATER PUMP ........................................................... 53
Components ............................................................ 53
Removal and Installation ......................................... 53
REMOVAL ............................................................ 53
INSPECTION AFTER REMOVAL ........................ 54
INSTALLATION .................................................... 54
INSPECTION AFTER INSTALLATION ................ 54
THERMOSTAT AND WATER CONTROL VALVE ..... 55
Components ............................................................ 55
Removal and Installation ......................................... 55
REMOVAL ............................................................ 55
INSPECTION AFTER REMOVAL ........................ 56
INSTALLATION .................................................... 56
INSPECTION AFTER INSTALLATION ................ 57
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 58
Standard and Limit .................................................. 58
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 58
RADIATOR ........................................................... 58
THERMOSTAT ..................................................... 58
WATER CONTROL VALVE .................................. 58

OVERHEATING CAUSE ANALYSIS
CO-7
[VQ35DE]
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Revision: 2006 January2006 M35/M45
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartNBS004QN
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.)
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

ENGINE COOLANT
CO-11
[VQ35DE]
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ENGINE COOLANTPFP:KQ100
InspectionNBS004QQ
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).
WAR NING :
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 CoolantNBS004QR
WAR NING :
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 engine room cover (RH and LH). Refer to EM-14, "ENGINE ROOM COVER" .
2. Remove air duct (inlet). Refer to EM-17, "
AIR CLEANER AND AIR DUCT" .
3. 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" .
SMA412B
Testing pressure
: 157 kPa (1.6 kg/cm
2 , 23 psi)
SLC756A
1 : Radiator drain plug hole
2 : Front engine under cover
: Engine front
PBIC3395E

CO-12
[VQ35DE]
ENGINE COOLANT
Revision: 2006 January2006 M35/M45
4. Remove reservoir tank as necessary, and drain engine coolant and clean reservoir tank before installing.
5. Check drained engine coolant for contaminants such as rust, corrosion or discoloration.
If contaminated, flush the engine cooling system. Refer to CO-13, "
FLUSHING COOLING SYSTEM" .
REFILLING ENGINE COOLANT
1. Install reservoir tank if removed, and radiator drain plug.
CAUTION:
Be sure to clean drain plug and install with new O-ring.
If water drain plugs on cylinder block are removed, close and tighten them. Refer to EM-128,
"ASSEMBLY" .
2. Make sure that each hose clamp has been firmly tightened.
3. Remove air relief plug on heater hose.
4. Fill radiator, and reservoir tank if removed, to specified level.
Pour engine coolant through engine coolant filler neck
slowly of less than 2 (2-1/8 US qt, 1-3/4 lmp qt) a minute
to allow air in system to escape.
Use Genuine Nissan Long Life Antifreeze/Coolant or
equivalent mixed with water (distilled or demineralized).
Refer to MA-12, "
RECOMMENDED FLUIDS AND LUBRI-
CANTS" .
When engine coolant overflows air relief hole on heater hose,
install air relief plug with new O-ring.
5. Install radiator cap.
6. Warm up engine until opening thermostat. Standard for warming-up time is approximately 10 minutes at
3,000 rpm.
Make sure thermostat opening condition by touching radiator hose (lower) to see a flow of warm water.
CAUTION:
Watch water temperature gauge so as not to overheat engine.Radiator drain plug:
: 1.2 Nꞏm (0.12 kg-m, 11 in-lb)
SBIA0445E
Engine coolant capacity
(With reservoir tank at “MAX” level)
: Approximately 8.9 (9-3/8 US qt, 7-7/8 lmp qt)
SMA182B
Reservoir tank engine coolant capacity
(At “MAX” level)
: 0.6 (5/8 US qt, 1/2 lmp qt)
Air relief plug:
: 1.2 Nꞏm (0.12 kg-m, 11 ft-lb)
SMA412B

ENGINE COOLANT
CO-13
[VQ35DE]
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7. Stop the engine and cool down to less than approximately 50C (122F).
Cool down using fan to reduce the time.
If necessary, refill radiator up to filler neck with engine coolant.
8. Refill reservoir tank to “MAX” level line with engine coolant.
9. Repeat steps 4 through 7 two or more times with radiator cap installed until engine coolant level no longer
drops.
10. Check cooling system for leaks with engine running.
11. Warm up the engine, and check for sound of engine coolant flow while running engine from idle up to
3,000 rpm with heater temperature controller set at several position between “COOL” and “WARM”.
Sound may be noticeable at heater unit.
12. Repeat step 11 three times.
13. If sound is heard, bleed air from cooling system by repeating step 4 through 7 until engine coolant level no
longer drops.
FLUSHING COOLING SYSTEM
1. Install reservoir tank if removed, and radiator drain plug.
CAUTION:
Be sure to clean drain plug and install with new O-ring.
If water drain plugs on cylinder block are removed, close and tighten them. Refer to EM-128,
"ASSEMBLY" .
2. Remove air relief plug on heater hose.
3. Fill radiator with water until water spills from the air relief hole, then close air relief plug. Fill radiator and
reservoir tank with water and reinstall radiator cap.
4. Run the engine and warm it up to normal operating temperature.
5. Rev the engine two or three times under no-load.
6. Stop the engine and wait until it cools down.
7. Drain water from the system. Refer to CO-11, "
DRAINING ENGINE COOLANT" .
8. Repeat steps 1 through 7 until clear water begins to drain from radiator. Radiator drain plug:
: 1.2 Nꞏm (0.12 kg-m, 11 in-lb)
SBIA0445E
Air relief plug:
: 1.2 Nꞏm (0.12 kg-m, 11 ft-lb)

CO-14
[VQ35DE]
RADIATOR
Revision: 2006 January2006 M35/M45
RADIATORPFP:21400
ComponentsNBS004QS
Refer to GI-11, "Components" for symbol marks in the figure.
Removal and InstallationNBS004QT
WAR NING :
Do not remove radiator cap when engine is hot. Serious burns could occur from high-pressure engine
coolant escaping from radiator. Wrap a thick cloth around the cap. Slowly turn it a quarter of a turn to
release built-up pressure. Carefully remove radiator cap by turning it all the way.
REMOVAL
1. Remove the following parts:
Front engine undercover (power tool).
Engine room cover (RH and LH). Refer to EM-14, "ENGINE ROOM COVER" .
Air duct (inlet) and air cleaner case assembly. Refer to EM-17, "AIR CLEANER AND AIR DUCT" .
1. Reservoir tank cap 2. Reservoir tank 3. Reservoir tank bracket
4. Reservoir tank hose 5. Radiator hose (upper) 6. Air guide
7. Mount bracket (RH) 8. Mounting rubber (upper) 9. A/C condenser
10. Radiator cap 11. Mount bracket (LH) 12. Radiator
13. Mounting rubber (lower) 14. A/T fluid cooler hose 15. A/T fluid cooler hose
16. O-ring 17. Drain plug 18. Radiator hose (lower)
19. Cooling fan assembly
A. To water outlet B. To water inlet C. To transmission
D. To transmission
PBIC4717E