2001 INFINITI QX4 radiator

SLC756A
CHECKING COOLING SYSTEM FOR LEAKSNBLC0016S04To check for leakage, apply pressure to the cooling system with a
tester.
Testing pressure:
157 kPa (1.6 kg/cm
2, 23 psi)
CAUTION:
Higher than the specified pressure may cause radiator
damage.
Water Pump
REMOVAL AND INSTALLATIONNBLC0017CAUTION:
IWhen removing water pump assembly, be careful not to
get coolant on drive belt.
IWater pump cannot be disassembled and should be
replaced as a unit.
IAfter installing water pump, connect hose and clamp
securely, then check for leaks using radiator cap tester.
SLC326B
SLC327B
REMOVALNBLC00181. Remove under cover.
2. Remove suspension member stay.
3. Drain coolant from radiator.
4. Remove radiator shrouds.
5. Remove drive belts.
6. Remove cooling fan.
7. Remove water drain plug on water pump side of cylinder block.
8. Remove chain tensioner cover and water pump cover.
ENGINE COOLING SYSTEM
System Check (Cont'd)
LC-12

Thermostat
REMOVAL AND INSTALLATIONNBLC0021
SLC329B
SLC962AA
1. Remove under cover.
2. Remove suspension member stay.
3. Drain coolant from radiator.
4. Remove drive belts.
5. Remove water drain plug on water pump side of cylinder block.
6. Disconnect lower radiator hose.
7. Remove water inlet and thermostat assembly.
IDo not disassemble water inlet and thermostat. Replace
them as a unit, if necessary.
SLC948A
8. Install thermostat with jiggle valve facing upward.
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.
9. Reinstall any removed parts in reverse order of removal.
SLC949A
INSPECTIONNBLC00221. 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 76.5ÉC (170ÉF)
Valve lift More than 8.6 mm/90ÉC
(0.339 in/194ÉF)
ENGINE COOLING SYSTEM
Thermostat
LC-16

3. Then check if valve closes at 5ÉC (9ÉF) below valve opening
temperature.
Water Control Valve
REMOVAL AND INSTALLATIONNBLC0032
SLC330B
1. Water outlet housing
2. Water control valve
3. Water outlet4. Water hose
5. Cylinder block water outlet
6. Thermal transmitter7. Engine coolant temperature sen-
sor
1. Release fuel pressure.
Refer to EC-39, ªFuel Pressure Releaseº.
2. Remove under cover.
3. Remove suspension member stay.
4. Drain coolant from radiator.
5. Remove engine cover.
6. Remove air duct with air cleaner assembly.
7. Disconnect wires, hoses, harness and so on.
8. Remove upper intake manifold corrector.
9. Remove intake manifold corrector support bolts.
10. Remove lower intake manifold corrector.
11. Disconnect injector harness connectors.
12. Remove injector tube.
13. Remove intake manifold.
14. Remove water outlet housing and water control valve.
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ENGINE COOLING SYSTEM
Thermostat (Cont'd)
LC-17

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

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