2006 INFINITI M35 engine cooling

ENGINE COOLANT
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Revision: 2006 January2006 M35/M45
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
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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
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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)
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Air relief plug:
: 1.2 Nꞏm (0.12 kg-m, 11 ft-lb)

CO-14
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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

RADIATOR
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Revision: 2006 January2006 M35/M45
2. Remove front grille and front grille support. Refer to EI-16, "FRONT GRILLE" .
NOTE:
If stopping at the removal and installation of the cooling fan assembly, this procedure is not necessary.
3. Drain engine coolant from radiator. Refer to CO-11, "
Changing Engine Coolant" .
CAUTION:
Perform this step when the engine is cold.
Do not spill engine coolant on drive belts.
4. Remove the A/C piping bracket from left side member, and then move the A/C piping out of the way.
5. Disconnect A/T fluid cooler hoses from radiator.
Install blind plug to avoid leakage of A/T fluid.
6. Remove radiator hoses (upper and lower) and reservoir tank hose.
CAUTION:
Be careful not to allow engine coolant to contact drive belts.
7. Remove cooling fan assembly (1). Refer to CO-22, "
COOLING
FAN" .
CAUTION:
Do not damage or scratch radiator core when removing.
8. Remove radiator as follows:
a. Remove mount bracket (RH and LH).
b. Pull the radiator (1) rearward from the vehicle, and then remove
the mounting bolts (3) and A/C condenser (2).
NOTE:
Figure shows right side.
c. Lift up and pull the radiator (4) rearward, and then remove the mounting rubber (lower) (3) from the radia-
tor core support (2).
CAUTION:
At this time, A/C condenser is on the lower end of radiator
front surface. Minimize the movement to the rear side.
d. Lift up the A/C condenser to disengage the lower end of front surface, and then remove the radiator.
CAUTION:
Be careful not to damage radiator and A/C condenser core.
KBIA3587J
KBIA3586J
1 : A/C condenser
: Engine front
PBIC3389E

CO-22
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COOLING FAN
Revision: 2006 January2006 M35/M45
COOLING FANPFP:21140
ComponentsNBS004QY
Removal and Installation NBS004QZ
REMOVAL
1. Remove engine room cover (RH and LH). Refer to EM-14, "ENGINE ROOM COVER" .
2. Remove air duct (inlet) and air cleaner case assembly. Refer to EM-17, "
AIR CLEANER AND AIR DUCT"
.
3. Drain engine coolant from radiator. Refer to CO-11, "
ENGINE COOLANT" .
4. Disconnect harness connector from cooling fan control module, and move harness to aside.
5. Remove radiator hose (upper). Refer to CO-14, "
RADIATOR" .
6. Remove cooling fan assembly.
CAUTION:
Be careful not to damage or scratch on radiator core.
INSTALLATION
Note the following, and install in the reverse order of removal.
CAUTION:
Only use genuine parts for radiator shroud and cooling fan mounting bolt and observe the specified
torque (to prevent radiator from being damaged).
INSPECTION AFTER INSTALLATION
Make sure that fan motors operate normally.
1. Sub-harness 2. Cooling fan control module 3. Sub-harness
4. Fan motor (LH) 5. Fan motor (RH) 6. Fan shroud
7. Cooling fan (RH) 8. Cooling fan (LH)
A. Apply on fan motor shaft.
Apply Genuine High Strength Lock-
ing Sealant or equivalent.
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COOLING FAN
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Revision: 2006 January2006 M35/M45
NOTE:
Cooling fans are controlled by cooling fan control module. For details, refer to EC-512, "
DTC P1217 ENGINE
OVER TEMPERATURE" .
Disassembly and Assembly NBS004R0
DISASSEMBLY
1. Disconnect sub-harness from fan motor (RH and LH) and cooling fan control module.
2. Remove cooling fan control module from fan shroud.
CAUTION:
Handle carefully to avoid dropping and shocks.
3. Remove cooling fan mounting nuts, and then remove the cooling fan (RH and LH).
4. Remove fan motor (RH and LH).
INSPECTION AFTER DISASSEMBLY
Cooling Fan
Inspect cooling fan for crack or unusual bend.
If anything is found, replace cooling fan.
ASSEMBLY
Note the following, and assemble in the reverse order of disassembly.
CAUTION:
RH and LH cooling fans are different. Be careful not to misassemble them.
Install each fan in the following position.
Secure the sub-harness tightly to the fan shroud to prevent the fan rotation area from being loose. Right side : 4 fans
Left side : 5 fans

CO-36
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OVERHEATING CAUSE ANALYSIS
Revision: 2006 January2006 M35/M45
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartNBS004RB
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat and water con-
trol valve 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