engine cooling INFINITI M35 2006 Factory Owner's Manual

RADIATOR
CO-15
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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.
KBIA3567J

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

CO-40
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ENGINE COOLANT
Revision: 2006 January2006 M35/M45
ENGINE COOLANTPFP:KQ100
InspectionNBS004RE
LEVEL CHECK
Check if the reservoir tank engine coolant level is within the
“MIN” to “MAX” when engine is cool.
Adjust the engine coolant level as necessary.
LEAK CHECK
To check for leaks, apply pressure to the cooling system with
radiator cap tester (commercial service tool) and radiator cap
tester adapter (SST).
WA R N I N G :
Do not remove radiator cap when engine is hot. Serious
burns could occur from high-pressure engine coolant
escaping from thermostat housing.
CAUTION:
Higher testing pressure than specified may cause radiator
damage.
NOTE:
In a case engine coolant decreases, replenish radiator with engine coolant.
If anything is found, repair or replace damaged parts.
Changing Engine CoolantNBS004RF
WAR NING :
To avoid being scalded, do not change engine coolant when 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-173, "ENGINE ROOM COVER" .
2. Remove engine cover with power tool. Refer to EM-179, "
INTAKE MANIFOLD" .
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-250, "
DISASSEMBLY" .
4. Remove reservoir tank as necessary, and drain engine coolant and clean reservoir tank before installing.
SMA412B
Testing pressure : 157 kPa (1.6 kg/cm2 , 23 psi)
PBIC1528E
1 : Radiator drain plug hole
2 : Front engine undercover
: Engine front
PBIC3395E

ENGINE COOLANT
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Revision: 2006 January2006 M35/M45
5. Check drained engine coolant for contaminants such as rust, corrosion or discoloration.
If contaminated, flush the engine cooling system. Refer to CO-42, "
FLUSHING COOLING SYSTEM" .
REFILLING ENGINE COOLANT
1. Install reservoir tank if removed, and radiator drain plug.
CAUTION:
Be sure to clean radiator drain plug and install with new O-ring.
If water drain plugs on cylinder block are removed, close and tighten them. Refer to EM-254,
"ASSEMBLY" .
2. Make sure that each hose clamp has been firmly tightened.
3. Remove air relief plug (1) on heater hose.
4. Fill thermostat housing and reservoir tank to specified level.
Refill engine coolant up to filler neck of thermostat housing.
Pour engine coolant through engine coolant filler neck slowly of less than 2 (2-1/8 US qt, 1-3/4
Imp 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 LUBRICANTS" .
When engine coolant overflows air relief hole on heater hose,
install air relief plug.
5. Install radiator cap.
6. Warm up 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.
7. Stop engine and cool down to less than approximately 50
C (122F).
Cool down using a fan to reduce the time.Radiator drain plug:
: 1.2 Nꞏm (0.12 kg-m, 11 in-lb)
: Engine front
PBIC3394E
Engine coolant capacity
(With reservoir tank at “MAX” level):
Approx. 10.4 (11 US qt, 9-1/8 Imp qt)
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 in-lb)
SMA412B

CO-42
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ENGINE COOLANT
Revision: 2006 January2006 M35/M45
If necessary, refill engine coolant up to filler neck of thermostat housing.
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 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 steps 4 through 7 until engine coolant level
no longer drops.
FLUSHING COOLING SYSTEM
1. Install reservoir tank, 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-254,
"ASSEMBLY" .
2. Remove air relief plug (1) on heater hose.
3. Fill thermostat housing with water until water spills from the air relief hole, then close air relief plug. Fill
thermostat housing and reservoir tank with water and reinstall radiator cap.
4. Run engine and warm it up to normal operating temperature.
5. Rev engine two or three times under no-load.
6. Stop engine and wait until it cools down.
7. Drain water from the system. Refer to CO-40, "
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)
: Engine front
PBIC3394E
Air relief plug:
: 1.2 Nꞏm (0.12 kg-m, 11 in-lb)

RADIATOR
CO-43
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Revision: 2006 January2006 M35/M45
RADIATORPFP:21400
ComponentsNBS004RG
Refer to GI-11, "Components" for symbol marks in the figure.
Removal and InstallationNBS004RH
WAR NING :
Do not remove radiator cap when engine is hot. Serious burns could occur from high-pressure engine
coolant escaping from thermostat housing. Wrap a thick cloth around radiator 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-173, "ENGINE ROOM COVER" .
Air duct (inlet) and air cleaner case assembly. Refer to EM-177, "AIR CLEANER AND AIR DUCT" .
2. Remove front grille and front grille support. Refer to EI-16, "
FRONT GRILLE" .
3. Drain engine coolant from radiator. Refer to CO-40, "
ENGINE COOLANT" .
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. Mount bracket (LH) 11. Radiator 12. Mounting rubber (lower)
13. A/T fluid cooler hose 14. A/T fluid cooler hose 15. O-ring
16. Drain plug 17. Radiator hose (lower) 18. Cooling fan assembly
A. To thermostat housing B. To water suction pipe C. To transmission
PBIC4718E

CO-44
[VK45DE]
RADIATOR
Revision: 2006 January2006 M35/M45
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-51, "
COOLING
FA N" .
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.
Minimize the lift of A/C condenser to prevent load from being applied to A/C piping.
e. After removing the radiator, place the A/C condenser on the radiator core support to prevent load from
being applied to piping. And then, temporarily secure them using a rope to prevent them from being
dropped.
KBIA3587J
KBIA3586J
1 : A/C condenser
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PBIC3389E

RADIATOR
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Revision: 2006 January2006 M35/M45
INSTALLATION
Installation is the reverse order of removal.
INSPECTION AFTER INSTALLATION
Check for leaks of engine coolant using radiator cap tester adapter [SST: EG17650301 (J33984-A)] and
radiator cap tester (commercial service tool). Refer to CO-40, "
LEAK CHECK" .
Start and warm up engine. Visually Check if there is no leaks of engine coolant and A/T fluid.
Checking Radiator CapNBS004RI
Check valve seat of radiator cap.
–Check if valve seat is swollen to the extent that the edge of the
plunger cannot be seen when watching it vertically from the top.
–Check if valve seat has no soil and damage.
Pull negative-pressure valve to open it, and make sure that it
close completely when released.
–Make sure that there is no dirt or damage on the valve seat of
radiator cap negative-pressure valve.
–Make sure that there are no unusualness in the opening and
closing conditions of negative-pressure valve.
Check radiator cap relief pressure.
–When connecting radiator cap to the radiator cap tester adapter
(SST) and the radiator cap tester (Commercial service tool),
apply engine coolant to the cap seal surface.
Replace radiator cap if there is an unusualness.
CAUTION:
When installing a radiator cap, thoroughly wipe out the radiator filler neck to remove any waxy residue
or foreign material.
Checking RadiatorNBS004RJ
Check radiator for mud or clogging. If necessary, clean radiator as follows:
Be careful not to bend or damage the radiator fins.
When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radiator
shroud and horns. Then tape the harness and electrical connectors to prevent water from entering.
1. Apply water by hose to the back side of the radiator core vertically downward.
2. Apply water again to all radiator core surface once per minute.
PBIC2816E
SMA967B
Standard : 78 - 98 kPa (0.8 - 1.0 kg/cm2 , 11 - 14 psi)
Limit : 59 kPa (0.6 kg/cm
2 , 9 psi)
SLC755A