2001 INFINITI QX4 Ac system

SLC334B
15. Install water control valve and water outlet housing.
a. Install gum ring to thermostat.
b. Point the arrow on the upper surface of the valve to the front
of the engine, and also be sure to install the protrusions and
the valve stopper so that they are aligned in a straight line.
16. Reinstall any removed parts in reverse order of removal.
IWhen installing intake manifold, injector tube and intake
manifold collectors, refer to EM-12, ªTIGHTENING PROCE-
DURESº.
IAfter installation, run engine for a few minutes, and check
for leaks.
IBe careful not to spill coolant over engine compartment.
Use a rag to absorb coolant.
SLC252B
INSPECTIONNBLC00331. Check valve seating condition at ordinary room temperatures.
It should seat tightly.
2. Check valve opening temperature and maximum valve lift.
Standard
Valve opening temperature 95ÉC (203ÉF)
Valve lift More than 8.0 mm/108ÉC
(0.315 in/226ÉF)
3. Then check if valve closes at 5ÉC (9ÉF) below valve opening
temperature.
ENGINE COOLING SYSTEM
Water Control Valve (Cont'd)
LC-18

Radiator
REMOVAL AND INSTALLATION=NBLC00231. Remove under cover.
2. Remove suspension member stay.
3. Drain coolant from radiator.
4. Disconnect radiator upper and lower hoses.
5. Remove upper and lower radiator shroud.
6. Remove A/T oil cooler hoses.
7. Disconnect reservoir tank hose.
8. Remove radiator mounting bracket.
9. Remove radiator.
10. After repairing or replacing radiator, install any part removed in reverse order of removal.
When filling radiator with coolant, refer to MA-14, ªChanging Engine Coolantº.
SLC331B
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ENGINE COOLING SYSTEM
Radiator
LC-19

SLC066B
Cooling Fan (Crankshaft driven)
REMOVAL AND INSTALLATION=NBLC0038IDo not release the drive belt tension by removing the fan/water
pump pulley.
IFan coupling cannot be disassembled and should be replaced
as a unit. If front markFis present, install fan so that side
markedFfaces the front.
IInstall the drive belt only after the fan and fan coupling to water
pump flange bolts/nuts have been properly torqued.
IProper alignment of these components is essential. Improper
alignment will cause them to wobble and may eventually cause
the fan to separate from the water pump causing extensive
damage.
SLC067B
INSPECTIONNBLC0039Check fan coupling for rough operation, wobbling, oil leakage or
bent bimetal.
SLC151B
After assembly, verify the fan does not wobble or flap while the
engine is running.
WARNING:
IWhen the engine is running, keep hands and clothing
away from moving parts such as drive belts and fan.
Refilling Engine CoolantNBLC0034For details on refilling engine coolant, refer to MA-15, ªREFILLING
ENGINE COOLANTº.
ENGINE COOLING SYSTEM
Cooling Fan (Crankshaft driven)
LC-20

Radiator (Aluminum type)
PREPARATIONNBLC0025
SLC882AB
SLC655CB
1. Attach the spacer to the tip of the radiator plate pliers A. Spacer
specification: 1.5 mm (0.059 in) thick x 18 mm (0.71 in) wide
x 8.5 mm (0.335 in) long.
2. Make sure that when radiator plate pliers A are closed dimen-
sion H¢¢is approx. 7.6 mm (0.299 in).
3. Adjust dimension H¢¢with the spacer, if necessary.
SLC903-A
DISASSEMBLYNBLC00261. Remove tank with Tool.
SLC893
IGrip the crimped edge and bend it upwards so that Tool slips
off.
Do not bend excessively.
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ENGINE COOLING SYSTEM
Radiator (Aluminum type)
LC-21

SLC930
IIn areas where Tool cannot be used, use a screwdriver to bend
the edge up.
Be careful not to damage tank.
SLC931
2. Make sure the edge stands straight up.
3. Remove oil cooler from tank.
SLC894
ASSEMBLYNBLC00271. Install oil cooler.
Pay attention to direction of conical washer.
SLC932
2. Clean contact portion of tank.
SLC917A
3. Install sealing rubber.
Push it in with fingers.
Be careful not to twist sealing rubber.
ENGINE COOLING SYSTEM
Radiator (Aluminum type) (Cont'd)
LC-22

SLC904-A
4. Caulk tank in specified sequence with Tool.
SLC896
SLC897
IUse pliers in the locations where Tool cannot be used.
SLC554A
5. Make sure that the rim is completely crimped down.
Standard height ªHº:
8.0 - 8.4 mm (0.315 - 0.331 in)
6. Confirm that there is no leakage.
Refer to Inspection.
SLC933-A
INSPECTIONNBLC0028Apply pressure with Tool.
Specified pressure value:
157 kPa (1.6 kg/cm
2, 23 psi)
WARNING:
To prevent the risk of the hose coming undone while under
pressure, securely fasten it down with a hose clamp.
Attach a hose to the oil cooler as well.
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ENGINE COOLING SYSTEM
Radiator (Aluminum type) (Cont'd)
LC-23

Overheating Cause AnalysisNBLC0029
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
Ð Thermostat stuck closed Ð
Damaged finsDust contamination or
paper clogging
Mechanical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Reduced air flowCooling fan does not oper-
ate
ÐÐ High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud Ð Ð Ð
Improper coolant mixture
ratioÐÐÐ
Poor coolant quality Ð Ð Ð
Insufficient coolantCoolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, dete-
rioration or improper fit-
ting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deteriora-
tion
Cylinder head gasket
deterioration
ENGINE COOLING SYSTEM
Overheating Cause Analysis
LC-24

Symptom Check items
Except cool-
ing system
parts mal-
functionÐ Overload on engineAbusive drivingHigh engine rpm under
no load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system malfunc-
tion
Ð Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper Ð
Ð Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator Ð
Blocked condenser
Ð
Installed large fog lamp
Service Data and Specifications (SDS)
THERMOSTATNBLC0030
Valve opening temperature76.5ÉC (170ÉF)
Valve liftMore than 8.6 mm/90ÉC (0.339 in/194ÉF)
WATER CONTROL VALVENBLC0035
Valve opening temperature95ÉC (203ÉF)
Valve liftMore than 8.0 mm/108ÉC (0.315 in/226ÉF)
RADIATORNBLC0031Unit: kPa (kg/cm2, psi)
Cap relief pressureStandard 78 - 98 (0.8 - 1.0, 11 - 14)
Limit 59 - 98 (0.6 - 1.0,9-14)
Leakage test pressure157 (1.6, 23)
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ENGINE COOLING SYSTEM
Overheating Cause Analysis (Cont'd)
LC-25