1998 NISSAN PICK-UP overheating

Overheat
ON BOARD DIAGNOSIS LOGIC
If the cooling fan or another component in the cooling system malfunctions, the engine coolant temperature
will rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Diagnostic trouble
code No.Malfunction is detected when ...Check Items
(Possible Cause)
28
lEngine coolant temperature reaches an abnormally
high temperature.lCooling fan
lRadiator hose
lRadiator
lRadiator cap
lWater pump
lThermostat
For more information, refer to ``MAIN 12
CAUSES OF OVERHEATING'', EC-108.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in MA sec-
tion (``Changing Engine Coolant'', ``ENGINE MAINTENANCE''). Also, replace the engine oil.
lFill radiator with coolant up to specified level with a filling speed of 2 liters per minute like pour-
ing coolant by kettle. Be sure to use coolant with the proper mixture ratio. Refer to MA section
(``Anti-freeze Coolant Mixture Ratio'', ``RECOMMENDED FLUIDS AND LUBRICANTS'').
lAfter refilling coolant, run engine to ensure that no water-flow noise is emitted.
OVERALL FUNCTION CHECK
WARNING:
Never remove the radiator cap when the engine is hot. Seri-
ous burns could be caused by high pressure fluid escaping
from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by
turning it a quarter turn to allow built-up pressure to escape.
Then turn the cap all the way off.
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is
below the proper range, skip the following step and go to
``DIAGNOSTIC PROCEDURE'' on next page.
2. Confirm whether customer filled the coolant or not. If cus-
tomer filled the coolant, go to ``DIAGNOSTIC PROCEDURE''
on next page.
AEC640
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
EC-106

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK COOLING SYSTEM FOR LEAK.
Apply pressure to the cooling system with a
tester, and check if the pressure drops.
Testing pressure:
157 kPa (1.57 bar, 1.6 kg/cm
2, 23 psi)
Pressure should not drop.
CAUTION:
Higher than the specified pressure may
cause radiator damage.
OK
cNG
Check the following for leak.
lHoselRadiatorlWater pump
Refer to LC section (``Water
Pump'').
CHECK RADIATOR CAP.
Apply pressure to cap with a tester.
Radiator cap relief pressure:
78 - 98 kPa (0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
OK
cNG
Replace radiator cap.
CHECK THERMOSTAT.
1. Check valve seating condition at normal
room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve
lift.
Valve opening temperature:
76.5ÉC (170ÉF) [standard]
Valve lift:
More than 10 mm/90ÉC
(0.39 in/194ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below
valve opening temperature.
For details, refer to LC section (``Thermostat'').
OK
cNG
Replace thermostat.
Check engine coolant temperature sensor.
Refer to ``COMPONENT INSPECTION'',
EC-98.
OK
cNG
Replace engine coolant tem-
perature sensor.
If the cause cannot be isolated, go to ``MAIN
12 CAUSES OF OVERHEATING'' on next
page.
INSPECTION END
Perform FINAL CHECK by the following procedure after
repair is completed.
1. Warm up engine. Run the vehicle for at least 20 minutes. Pay
attention to engine coolant temperature gauge on the instru-
ment panel. If the reading shows an abnormally high
temperature, another part may be malfunctioning.
2. Stop vehicle and let engine idle. Check the intake and exhaust
systems for leaks by listening for noise or visually inspecting
the components.
3. Allow engine to cool and visually check for oil and coolant
leaks. Then, perform ``OVERALL FUNCTION CHECK''.
SLC754AA
SLC755AA
SLC343
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
Overheat (Cont'd)
EC-107

MAIN 12 CAUSES OF OVERHEATING
Engine Step Inspection item Equipment Standard Reference page
OFF 1
lBlocked radiator
lBlocked condenser
lBlocked radiator grille
lBlocked bumper
lVisual No blocking Ð
2
lCoolant mixturelCoolant tester 50 - 50% coolant mixture See ``RECOMMENDED
FLUIDS AND LUBRI-
CANTS'' in MA section.
3
lCoolant levellVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
4
lRadiator caplPressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
59 - 98 kPa (0.59 - 0.98
bar, 0.6 - 1.0 kg/cm
2,
9 - 14 psi) (Limit)See ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 5
lCoolant leakslVisual No leaks See ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 6
lThermostatlTouch the upper and
lower radiator hosesBoth hoses should be hot. See ``Thermostat'' and
``Radiator'', ``ENGINE
COOLING SYSTEM'' in
LC section.
ON*1 7
lCooling fanlVisual Operating See ``Cooling Fan'',
``ENGINE COOLING
SYSTEM'' in LC section.
OFF 8
lCombustion gas leaklColor checker chemical
tester 4 gas analyzerNegative Ð
ON*3 9
lCoolant temperature
gaugelVisual Gauge less than 3/4
when drivingÐ
lCoolant overflow to res-
ervoir tanklVisual No overflow during driving
and idlingSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
OFF*4 10
lCoolant return from res-
ervoir tank to radiatorlVisual Should be initial level in
reservoir tankSee ``ENGINE MAINTE-
NANCE'' in MA section.
OFF 11
lCylinder headlStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ``Inspection'', ``CYL-
INDER HEAD'' in EM
section.
12
lCylinder block and pis-
tonslVisual No scuffing on cylinder
walls or pistonSee ``Inspection'', ``CYL-
INDER BLOCK'' in EM
section.
*1: Engine running at idle.
*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.
For more information, refer to ``OVERHEATING CAUSE ANALYSIS'' in LC section.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
Overheat (Cont'd)
EC-108

ENGINE LUBRICATION &
COOLING SYSTEMS
SECTION
LC
CONTENTS
PRECAUTIONS AND PREPARATION..................... 1
Liquid Gasket Application Procedure .................... 1
Special Service Tools ............................................ 2
KA
ENGINE LUBRICATION SYSTEM............................ 3
Lubrication Circuit .................................................. 3
Oil Pressure Check ................................................ 4
Oil Pump ................................................................ 4
ENGINE COOLING SYSTEM.................................... 6
Cooling Circuit........................................................ 6
System Check ........................................................ 6
Water Pump ........................................................... 7
Thermostat ............................................................. 8
Radiator.................................................................. 9
Cooling Fan (Crankshaft driven).......................... 10
TD
ENGINE LUBRICATION SYSTEM.......................... 12
Lubrication Circuit ................................................ 12
Oil Pressure Check (On-vehicle service) ............ 13
Oil Pump .............................................................. 14
Oil Filter Bracket .................................................. 16
Oil Cooler ............................................................. 17Oil Jet ................................................................... 18
ENGINE COOLING SYSTEM.................................. 19
Cooling Circuit...................................................... 19
Cooling System Inspection .................................. 20
Water Pump and Cooling Fan (Camshaft
driven) .................................................................. 21
Thermostat ........................................................... 23
Radiator................................................................ 24
Refilling Engine Coolant ...................................... 24
ENGINE ROOM FAN MOTOR ELECTRICAL
CIRCUIT................................................................... 25
Wiring Diagram .................................................... 25
Cooling Fan (Motor driven) .................................. 26
Electrical Components Inspection ....................... 26
ENGINE COOLING SYSTEM.................................. 28
Radiator (Aluminum type) .................................... 28
Overheating Cause Analysis ............................... 31
SERVICE DATA AND SPECIFICATIONS (SDS)... 32
Engine Lubrication System (KA).......................... 32
Engine Cooling System (KA) ............................... 32
Engine Lubrication System (TD).......................... 32
Engine Cooling System (TD) ............................... 32
LC

Overheating Cause Analysis
Symptom Check items
Cooling
system 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 operate
ÐÐ Fan coupling does not operate
High resistance to fan rotation
Damaged fan blades
Damaged radiator shroud Ð Ð Ð
Improper coolant mixture ratio Ð Ð Ð
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, deteriora-
tion 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 deteriora-
tion
Except
cooling
system parts
malfunctionÐ Overload on engineAbusive drivingHigh engine rpm under no load
Driving in low gear for extended
time
Driving at extremely high speed
Powertrain system malfunction
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
ENGINE COOLING SYSTEM
LC-31