CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
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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
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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
CO-8
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OVERHEATING CAUSE ANALYSIS
Revision: 2006 January2006 M35/M45
Except cool-
ing system
parts mal-
function— Overload on engineAbusive drivingHigh engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system mal-
function
— Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper —
— Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator —
Blocked condenser
Blocked air flow
Installed large fog lamp Symptom Check items
ENGINE COOLANT
CO-11
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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
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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-16
[VQ35DE]
RADIATOR
Revision: 2006 January2006 M35/M45
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.
INSTALLATION
Installation is the reverse order of removal.
INSPECTION AFTER INSTALLATION
Check for leaks of engine coolant using the radiator cap tester adapter [SST: EG17650301 (J33984-A)]
and the radiator cap tester (commercial service tool). Refer to CO-11, "
LEAK CHECK" .
Start and warm up the engine. Visually make sure that there is no leaks of engine coolant and A/T fluid.
Checking Radiator CapNBS004QU
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 (com-
mercial service tool) and the radiator cap tester adapter (SST),
apply engine coolant to the cap seal surface.
Replace radiator cap if there is an unusualness related to the above three.
CAUTION:
When installing radiator cap, thoroughly wipe out the radiator filler neck to remove any waxy residue
or foreign material.
Checking RadiatorNBS004QV
Check radiator for mud or clogging. If necessary, clean radiator as follows.
Be careful not to bend or damage radiator fins.
PBIC2816E
SMA967B
Standard:
78 - 98 kPa (0.8 - 1.0 kg/cm
2 , 11 - 14 psi)
Limit:
59 kPa (0.6 kg/cm
2 , 9 psi)
SLC755A