engine INFINITI QX4 2001 Factory Service Manual

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

SLC328B
9. Pushing timing chain tensioner sleeve, apply a stopper pin so
it does not return. Then remove the chain tensioner assembly.
SLC941A
10. Remove the 3 water pump fixing bolts. Secure a gap between
water pump gear and timing chain, by turning crankshaft pul-
ley 20É backwards.
JLC357B
11. Put M8 bolts to two water pump fixing bolt holes.
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ENGINE COOLING SYSTEM
Water Pump (Cont'd)
LC-13

SLC116B
12. Tighten M8 bolts by turning half turn alternately until they reach
timing chain rear case.
IIn order to prevent damages to water pump or timing chain rear
case, do not tighten one bolt continuously. Always turn each
bolt half turn each time.
13. Lift up water pump and remove it.
IWhen lifting up water pump, do not allow water pump gear to
hit timing chain.
SLC943A
INSPECTIONNBLC00191. Check for badly rusted or corroded body assembly.
2. Check for rough operation due to excessive end play.
SLC244B
INSTALLATIONNBLC00201. Apply engine oil and coolant to O-rings as shown in the figure.
ENGINE COOLING SYSTEM
Water Pump (Cont'd)
LC-14

SLC031B
2. Install water pump.
IDo not allow cylinder block to nip O-rings when installing
water pump.
SLC944A
3. Before installing, remove all traces of liquid gasket from mat-
ing surface of water pump cover and chain tensioner cover
using a scraper.
Also remove traces of liquid gasket from mating surface of
front cover.
SLC945AA
4. Apply a continuous bead of liquid gasket to mating surface of
chain tensioner cover and water pump cover.
SLC156B
5. Return the crankshaft pulley to its original position by turning
it 20É forward.
SLC961A
6. Install timing chain tensioner, then remove the stopper pin.
IWhen installing the timing chain tensioner, engine oil
should be applied to the oil hole and tensioner.
IAfter starting engine, let idle for three minutes, then rev
engine up to 3,000 rpm under no load to purge air from the
high-pressure chamber of the chain tensioners. The
engine may produce a rattling noise. This indicates that
air still remains in the chamber and is not a matter of
concern.
7. Reinstall any parts removed in reverse order of removal.
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ENGINE COOLING SYSTEM
Water Pump (Cont'd)
LC-15

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

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