engine overheat INFINITI QX4 2001 Factory User Guide

5 CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Remove engine coolant temperature sensor.
2. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.
SEF304X
OK or NG
OK©GO TO 6.
NG©Replace engine coolant temperature sensor.
6 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-319.
©INSPECTION END
DTC P0217 COOLANT OVERTEMPERATURE ENRICHMENT PROTECTION
Diagnostic Procedure (Cont'd)
EC-318

Main 12 Causes of OverheatingNBEC0615
Engine Step Inspection item Equipment Standard Reference page
OFF 1IBlocked radiator
IBlocked condenser
IBlocked radiator grille
IBlocked bumperIVisual No blocking Ð
2ICoolant mixtureICoolant tester 50 - 50% coolant mixture See MA-11, ªRECOM-
MENDED FLUIDS AND
LUBRICANTSº.
3ICoolant levelIVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee MA-14, ªChanging
Engine Coolantº.
4IRadiator capIPressure tester 59 - 98 kPa
(0.6 - 1.0 kg/cm
2,9-14
psi) (Limit)See LC-11, ªSystem
Checkº.
ON*
25ICoolant leaksIVisual No leaks See LC-11, ªSystem
Checkº.
ON*
26IThermostatITouch the upper and
lower radiator hosesBoth hoses should be
hotSee LC-16, ªThermostatº
and LC-19, ªRadiatorº.
ON*
17*5ICooling fanICONSULT-II Operating See trouble diagnosis for
DTC P0217 (EC-314).
OFF 8ICombustion gas leakIColor checker chemi-
cal tester 4 Gas ana-
lyzerNegative Ð
ON*
39ICoolant temperature
gaugeIVisual Gauge less than 3/4
when drivingÐ
ICoolant overflow to
reservoir tankIVisual No overflow during driv-
ing and idlingSee MA-14, ªChanging
Engine Coolantº.
OFF*
410ICoolant return from
reservoir tank to radia-
torIVisual Should be initial level in
reservoir tankSee MA-13, ªENGINE
MAINTENANCEº.
OFF 11ICylinder headIStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See EM-42, ªInspectionº.
12ICylinder block and pis-
tonsIVisual No scuffing on cylinder
walls or pistonSee EM-63, ªInspectionº.
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
*5: Cooling fan is not applied to this vehicle.
For more information, refer to LC-24, ªOVERHEATING CAUSE ANALYSISº.
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DTC P0217 COOLANT OVERTEMPERATURE ENRICHMENT PROTECTION
Main 12 Causes of Overheating
EC-319

On Board Diagnosis LogicNBEC0182When a misfire occurs, engine speed will fluctuate. If the engine
speed fluctuates enough to cause the CKP sensor signal to vary,
ECM can determine that a misfire is occurring.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can dam-
age the three way catalyst (TWC) due to overheating, the MIL
will blink.
When a misfire condition occurs, the ECM monitors the CKP
sensor signal every 200 engine revolutions for a change.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC
on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC,
the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will
affect vehicle emissions), the MIL will only light when the mis-
fire is detected on a second trip. During this condition, the ECM
monitors the CKP sensor signal every 1,000 engine revolu-
tions.
A misfire malfunction can be detected on any one cylinder or
on multiple cylinders.
Malfunction is detected when multiple cylinders misfire, No. 1 cyl-
inder misfires, No. 2 cylinder misfires, No. 3 cylinder misfires, No.
4 cylinder misfires, No. 5 cylinder misfires and No. 6 cylinder
misfires.
Possible CauseNBEC0490IImproper spark plug
IInsufficient compression
IIncorrect fuel pressure
IThe injector circuit is open or shorted
IInjectors
IIntake air leak
IThe ignition secondary circuit is open or shorted
ILack of fuel
IDrive plate or flywheel
IHeated oxygen sensor 1 (front)
DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
On Board Diagnosis Logic
EC-320

Both High- and Low-pressure Sides are Too High.NBHA0032S01
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.
AC359A
IPressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce refrigerant until
specified pressure is
obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cool-
ing performance
"
1. Condenser fins are
clogged.
2. Improper fan rotation of
cooling fanIClean condenser.
ICheck and repair cooling
fan as necessary.
ILow-pressure pipe is not
cold.
IWhen compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2, 28 psi). It then
decreases gradually there-
after.Poor heat exchange in con-
denser
(After compressor operation
stops, high pressure
decreases too slowly.)
"
Air in refrigeration cycleEvacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each
engine cooling system.
IAn area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.
IPlates are sometimes cov-
ered with frost.IExcessive liquid refrigerant
on low-pressure side
IExcessive refrigerant dis-
charge flow
IExpansion valve is open a
little compared with the
specification.
"
1. Improper thermal valve
installation
2. Improper expansion valve
adjustmentReplace expansion valve.
High-pressure Side is Too High and Low-pressure Side is Too Low.NBHA0032S02
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
AC360A
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged
or crushed.ICheck and repair or
replace malfunctioning
parts.
ICheck lubricant for con-
tamination.
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TROUBLE DIAGNOSES
Insufficient Cooling (Cont'd)
HA-117

ENGINE LUBRICATION &
COOLING SYSTEMS
SECTION
LC
CONTENTS
ENGINE LUBRICATION SYSTEM..................................2
Precautions ..................................................................2
LIQUID GASKET APPLICATION PROCEDURE............2
Preparation ..................................................................2
SPECIAL SERVICE TOOLS........................................2
COMMERCIAL SERVICE TOOL..................................3
Lubrication Circuit ........................................................3
Oil Pressure Check......................................................4
Oil Pump ......................................................................5
REMOVAL AND INSTALLATION.................................5
DISASSEMBLY AND ASSEMBLY................................5
OIL PUMP INSPECTION............................................6
REGULATOR VALVE INSPECTION............................6
OIL FILTER...............................................................7
Oil Cooler .....................................................................7
REMOVAL AND INSTALLATION.................................7
INSPECTION.............................................................8
Service Data and Specifications (SDS).......................8
OIL PRESSURE........................................................8
REGULATOR VALVE.................................................8
OIL PUMP.................................................................8
ENGINE COOLING SYSTEM..........................................9
Precautions ..................................................................9
LIQUID GASKET APPLICATION PROCEDURE............9
Preparation ..................................................................9
SPECIAL SERVICE TOOLS........................................9
Cooling Circuit ...........................................................10
System Check............................................................ 11
CHECKING COOLING SYSTEM HOSES................... 11
CHECKING RADIATOR............................................ 11
CHECKING RADIATOR CAP.................................... 11
CHECKING COOLING SYSTEM FOR LEAKS............12
Water Pump ...............................................................12
REMOVAL AND INSTALLATION...............................12
REMOVAL...............................................................12
INSPECTION...........................................................14
INSTALLATION........................................................14
Thermostat .................................................................16
REMOVAL AND INSTALLATION...............................16
INSPECTION...........................................................16
Water Control Valve ...................................................17
REMOVAL AND INSTALLATION...............................17
INSPECTION...........................................................18
Radiator .....................................................................19
REMOVAL AND INSTALLATION...............................19
Cooling Fan (Crankshaft driven) ...............................20
REMOVAL AND INSTALLATION...............................20
INSPECTION...........................................................20
Refilling Engine Coolant ............................................20
Radiator (Aluminum type) ..........................................21
PREPARATION.......................................................21
DISASSEMBLY........................................................21
ASSEMBLY.............................................................22
INSPECTION...........................................................23
Overheating Cause Analysis .....................................24
Service Data and Specifications (SDS).....................25
THERMOSTAT........................................................25
WATER CONTROL VALVE.......................................25
RADIATOR..............................................................25
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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

SMA182B
ÐREFILLING ENGINE COOLANTÐNBMA0011S021. Install reservoir tank, radiator drain plug, and cylinder block
drain plugs.
IApply sealant to the thread of cylinder block drain plugs.
:8-11N´m(0.8 - 1.2 kg-m, 70 - 104 in-lb) Front side
: 18 - 21 N´m (1.8 - 2.2 kg-m, 13 - 15 ft-lb) Right side
2. Fill coolant up to the top of the radiator mouth. While filling,
tighten each air bleeding plug from where coolant overflows.
Fill in the coolant again up to top of the mouth.
3. Reservoir tank with coolant up to the MAX level and install
radiator cap.
Air relief plugs:
: 6.7 - 7.9 N´m (0.68 - 0.81 kg-m, 59 - 70 in-lb)
Use Geniune Nissan anti-freeze coolant or equivalent mixed
with demineralized water/distilled water.
For coolant mixture ratio, refer to ªRECOMMENDED FLUIDS AND
LUBRICANTSº, MA-11.
Coolant capacity (Without reservoir tank):
8.6(9-1/8 US qt, 7-5/8 Imp qt)
SMA412B
Reservoir tank capacity (for MAX level):
0.6(5/8 US qt, 1/2 Imp qt)
Pour coolant through coolant filler neck slowly to allow air in
system to escape.
4. Warm up engine to normal operating temperature.
5. Run engine at 3,000 rpm for 10 seconds and return to idle
speed.
IRepeat 2 or 3 times.
Watch coolant temperature gauge so as not to overheat the
engine.
6. Stop engine and cool it down.
ICool down using a fan to reduce the time.
7. Remove the radiator filler cap and check coolant level.
IIf necessary, refill radiator up to filler neck with coolant.
8. Refill reservoir tank to Max line with coolant.
9. Repeat steps 4 through step 8 two or more times.
10. Warm up engine, and check for sound of coolant flow while
running engine from idle up to 3,000 rpm with heater tempera-
ture control set at several positions between COOL and HOT.
ISound may be noticeable at heater water cock.
11. If sound is heard, bleed air from cooling system by repeating
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ENGINE MAINTENANCE
Changing Engine Coolant (Cont'd)
MA-15