
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 speci®ed pressure may
cause radiator damage.
OK
cNG
Check the following for
leak.
+Hose
+Radiator
+Water 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:
82ÉC (180ÉF) [standard]
Maximum valve lift:
More than 10 mm/95ÉC
(0.39 in/203ÉF)
3. Check if valve is closed at 5ÉC (9ÉF)
below valve opening temperature.
For details, refer to LC section (``Thermo-
stat'').
OK
cNG
Replace thermostat.
Check engine coolant temperature sensor.
Refer to ``COMPONENT INSPECTION'',
EC-82.
OK
cNG
Replace engine coolant
temperature 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 instrument
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
SLC755AB
SLC343
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-119

MAIN 12 CAUSES OF OVERHEATING
Engine Step Inspection item Equipment Condition Reference page
OFF 1+Blocked radiator
+Blocked radiator grille
+Blocked bumper+Visual No blocking Ð
2+Coolant mixture+Coolant tester 50 - 50% coolant mixture See ``RECOMMENDED
FLUIDS AND LUBRI-
CANTS'' in MA section.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator ®ller neckSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
4+Radiator cap+Pressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)See ``System Check''
``ENGINE COOLING
SYSTEM'' in LC section.
ON*
25+Coolant leaks+Visual No leaks See ``System Check''
``ENGINE COOLING
SYSTEM'' in LC section.
ON*
26+Thermostat+Touch the upper and
lower radiator hosesBoth hoses should be hot See ``Thermostat'' and
``Radiator'', ``ENGINE
COOLING SYSTEM'' in
LC section.
ON*
17+Cooling fan+CONSULT Operating See ``TROUBLE DIAG-
NOSIS FOR DTC 28'',
EC-113.
OFF 8+Combustion gas leak+Color checker chemical
tester 4 Gas analyzerNegative Ð
ON*
39+Coolant temperature
gauge+Visual Gauge less than 3/4
when drivingÐ
+Coolant over¯ow to res-
ervoir tank+Visual No over¯ow during driving
and idlingSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
OFF*
410+Coolant return from res-
ervoir tank to radiator+Visual Should be initial level in
reservoir tankSee ``ENGINE MAINTE-
NANCE'' in MA section.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1mm (0.004 in) Maxi-
mum distortion (warping)See ``Inspection'', ``CYL-
INDER HEAD'' in EM
section.
12+Cylinder block and pis-
tons+Visual No scuffing on cylinder
walls or pistonSee ``Inspection'', ``CYL-
INDER BLOCK'' in EM
section.
*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.
For more information, refer to ``OVERHEATING CAUSE ANALYSIS'' in LC section.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-120

Inspection
Visually check the condition of timing belt.
Replace if any abnormality is found.
Item to check Problem Cause
Tooth is broken/tooth root
is cracked.
SEM394A
+Camshaft jamming
+Distributor jamming
+Damaged camshaft/crankshaft oil seal
Back surface is cracked/
worn.
SEM395A
+Tensioner jamming
+Overheated engine
+Interference with belt cover
Side surface is worn.
+Belt corners are worn and round.
+Wicks are frayed and coming out.
SEM396A
+Improper installation of belt
+Malfunctioning crankshaft pulley plate/timing belt
plate
Teeth are worn.
+Canvas on tooth face is worn down.
+Canvas on tooth is ¯uffy, rubber layer is worn
down and faded white, or weft is worn down and
invisible.
SEM397A
+Poor belt cover sealing
+Coolant leakage at water pump
+Camshaft not functioning properly
+Distributor not functioning properly
+Excessive belt tension
Oil/Coolant or water is
stuck to belt. Ð+Poor oil sealing of each oil seal
+Coolant leakage at water pump
+Poor belt cover sealing
TIMING BELT
EM-18

Trouble Diagnoses for Abnormal Pressure
Whenever system's high or low-pressure side is abnormal, diagnose using a manifold gauge. The marker
above the gauge scale in the following table indicates the standard (normal) pressure range. Since the stan-
dard (normal) pressure differs from vehicle to vehicle, refer to HA-35 (``Ambient air temperature-to-operating
pressure table'').
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high and low-pressure
sides are too high.
AC359A
+Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge in
refrigeration cycle.Reduce refrigerant until speci-
®ed pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
¯
j
1Condenser ®ns are clogged.
j
2Improper fan rotation of
cooling fan.+Clean condenser.
+Check and repair cooling fan
as necessary.
+Low-pressure pipe is not
cold.
+When compressor is stopped
high-pressure value quickly
drops by approximately 196
kPa (2.0 bar, 2 kg/cm
2,28
psi). It then decreases gradu-
ally thereafter.Poor heat exchange in con-
denser.
(After compressor operation
stops, high pressure decreases
too slowly.)
¯
Air in refrigeration cycle.Evacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each engine
cooling system.
+An area of the low-pressure
pipe is colder than areas
near the evaporator outlet.
+Plates are sometimes cov-
ered with frost.+Excessive liquid refrigerant
on low-pressure side.
+Excessive refrigerant dis-
charge ¯ow.
+Expansion valve is open a
little compared with the
speci®cation.
¯
j
1Improper thermal valve
installation.
j
2Improper expansion valve
adjustment.Replace expansion valve.
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.+Check and repair or replace
malfunctioning parts.
+Check lubricant for contami-
nation.
TROUBLE DIAGNOSESMANUAL
HA-36

ENGINE LUBRICATION &
COOLING SYSTEMS
SECTION
LC
CONTENTS
PRECAUTIONS AND PREPARATION............................1
Liquid Gasket Application Procedure ..........................1
Special Service Tools ..................................................2
ENGINE LUBRICATION SYSTEM..................................3
Lubrication Circuit ........................................................3
Oil Pressure Check......................................................3
Oil Pump ......................................................................4
Oil Cooler .....................................................................7
Oil Jet...........................................................................7
Turbocharger ...............................................................8
ENGINE COOLING SYSTEM..........................................9
Cooling Circuit .............................................................9System Check..............................................................9
Water Pump ...............................................................10
Thermostat .................................................................12
Radiator .....................................................................14
Re®lling Engine Coolant ............................................14
Cooling Fan (Crankshaft driven) ...............................15
Cooling Fan (Motor driven)........................................15
Radiator (Aluminum type) ..........................................16
Overheating Cause Analysis .....................................20
SERVICE DATA AND SPECIFICATIONS (SDS)..........21
Engine Lubrication System ........................................21
Engine Cooling System .............................................21
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 ®nsDust contamination or paper
clogging
Mechanical damage
Clogged radiator cooling tubeExcess foreign material (rust,
dirt, sand, etc.)
Reduced air ¯owCooling 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 ®tting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Over¯owing 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 ¯owBlocked 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-20

4. Remove cylinder block drain plug located at left rear of cylin-
der block.
5. Drain coolant and install reservoir tank, cylinder block drain
plug and radiator drain plug.
6. Fill radiator with water and warm up engine.
7. Stop engine and wait until it cools down.
8. Repeat step 2 through step 7 two or three times.
9. Drain water.
ÐREFILLING ENGINE COOLANTÐ
10. Install reservoir tank, radiator drain plug, and cylinder block
drain plugs.
+Apply sealant to the thread of cylinder block drain plug.
Cylinder block drain plug:
:34-44Nzm (3.5 - 4.5 kg-m, 25 - 33 ft-lb)
11. Fill radiator and reservoir tank with coolant up to the MAX level
and install radiator cap.
For coolant mixture ratio, refer to MA-11.
Coolant capacity (With reservoir tank):!(Imp qt)
RHD models
Without rear heater 11.8 (10-3/8)
With rear heater 12.9 (11-3/8)
LHD models
Without rear heater 11.6 (10-1/4)
With rear heater 12.7 (11-1/8)
Reservoir tank capacity (for MAX level):
1.2!(1-1/8 Imp qt)
Pour coolant through coolant ®ller neck slowly to allow air in
system to escape.
12. Warm up engine to normal operating temperature.
13. Run engine at 2,000 rpm for 10 seconds and return to idle
speed.
+Repeat 2 or 3 times.
Watch coolant temperature gauge so as not to overheat the
engine.
14. Stop engine and cool it down.
+Cool down using a fan to reduce the time.
15. Remove the radiator ®ller cap and check coolant level.
+If necessary, re®ll radiator up to ®ller neck with coolant.
16. Re®ll reservoir tank to Max line with coolant.
17. Repeat step 12 through step 16 two or more times.
18. Warm up engine, and check for sound of coolant ¯ow while
running engine from idle up to 2,000 rpm with heater tempera-
ture control set at several positions between COOL and HOT.
+Sound may be noticeable at heater water cock.
19. If sound is heard, bleed air from cooling system by repeating
steps 12 through 16 until coolant level no longer drops.
+Clean excess coolant from engine.
SMA003D
SMA182B
SMA412B
SMA004D
ENGINE MAINTENANCE
Changing Engine Coolant (Cont'd)
MA-15