engine overheat MITSUBISHI MONTERO 1998 Service Manual
Page 629 of 1501
(1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Determine source of contamination, such as engine
coolant, fuel, metal particles, or water. Require
repair or replacement.
( 3) - Inoperative includes intermittent operation or out of
OEM specification. Some components may be serviceable;
check for accepted cleaning procedure.
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ENGINE COOLING SYSTEMS
NOTE: Overheating, poor engine performance, and insufficient
cabin heat can be affected by, but are not limited to,
all of the components in the engine cooling system.
ENGINE COVERS (OIL PAN, VALVE COVER, TIMING COVER)
ENGINE COVER (OIL PAN, VALVE COVER, TIMING COVER) INSPECTION \
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Condition Code Procedure
Attaching hardware
incorrect .............. B ............ Require replacement.
Attaching hardware
loose .................. A .. Require repair or replacement.
Attaching hardware
missing ................ C ............ Require replacement.
Baffle loose ............ 2 .. Suggest repair or replacement.
Baffle missing .......... C ............ Require replacement.
Bent, affecting
performance ............ A .. Require repair or replacement.
Bent, not affecting
performance ............ .. ....... No service suggested or
required.
Cracked (not leaking) ... 2 .. Suggest repair or replacement.
Leaking externally ...... A .. Require repair or replacement.
Leaking internally,
causing fluid
contamination .......... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Restricted passage ...... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
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ENGINE OIL
ENGINE OIL INSPECTION \
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Condition Code Procedure
Contaminated ............ A .. ( 1) Require replacement of oil
and filter.
Level high .............. B ... Determine source of incorrect
level and require repair.
Level low ............... B ... Determine source of incorrect
level and require repair.
Maintenance intervals ... 3 ... Suggest replacement to comply
with vehicle's OEM recommended
service intervals.
( 1) - Determine source of contamination, such as engine coolant,
fuel, metal particles, or water when changing oil. Require
Page 781 of 1501
ON-VEHICLE TESTING
GENERATOR TO BATTERY CONTINUITY TEST
NOTE: Check generator wiring harness connections and drive belt
tension and ensure battery is fully charged before
performing test.
1) Turn ignition off. Disconnect negative battery cable.
Remove output lead from generator terminal "B". See Fig. 1. Install a
100-amp or 130-amp ammeter in series with terminal "B" and
disconnected output lead. Install positive lead of ammeter to terminal
"B" and negative lead to disconnected output wire.
Fig. 1: Identifying Generator Terminals (Typical)
Courtesy of Mitsubishi Motor Sales of America
2) Install positive lead of digital voltmeter to terminal "B"
and negative lead to positive battery terminal. Install a tachometer
and reconnect negative battery cable.
3) Start and operate engine at 2500 RPM. Turn accessories on
and adjust engine speed until ammeter indicates slightly greater than
30 amps, and note voltmeter reading. If voltmeter indicates .3 volt or
less, system is okay.
4) If voltage is greater than .3 volt, check wiring between
generator terminal "B", fusible link and positive battery terminal. If
terminal is not sufficiently tight or if harness is discolored due to
overheating, repair as necessary and retest.
Page 968 of 1501
allowing metal objects to contact the battery posts and the
vehicle at the same time.
CAUTION: Never disconnect the battery while the engine is running;
doing so could damage the car's electrical components.
REPLACING BLOWN FUSES
Before replacing a blown fuse, remove ignition key, turn off
all lights and accessories to avoid damaging the electrical system. Be
sure to use fuse with the correct indicated amperage rating. The use
of an incorrect amperage rating fuse may result in a dangerous
electrical system overload.
BRAKE PAD WEAR INDICATOR
Indicator will cause a squealing or scraping noise, warning
that brake pads need replacement.
BRAKE FLUID
WARNING: DO NOT use reclaimed fluid or fluid that has been stored
in old or open containers. It is essential that foreign
particles and other liquids are kept out of the brake fluid
reservoir.
CATALYTIC CONVERTER
Continued operation of vehicle with a severe malfunction
could cause converter to overheat, resulting in possible damage to
converter and vehicle.
ENGINE COOLANT SERVICE
WARNING: To avoid the danger of being scalded never change the coolant
when the engine is hot.
WARNING: Never remove the radiator cap when the engine is hot Serious
burns could be caused by high pressure fluid escaping from
the radiator.
CAUTION: When adding or replacing engine coolant, use a high quality
ethylene glycol antifreeze diluted with 50% distilled water.
When putting the cap on the reserve tank, line up the arrow
on the cap and the arrow on the tank, or coolant can leak out
ENGINE DRIVE BELT SERVICE
WARNING: Be sure the ignition key is OFF. The engine could rotate
unexpectedly.
ENGINE OIL
WARNING: The engine oil may be high enough to burn your fingers
when the drain plug is loosened. Wait until the drain plug
is cool enough to touch with you bare hands.
WARNING: Continuous contact with used engine oil has been found to
cause skin cancer in laboratory animals. Brief contact with
used engine oil may irritate skin. To minimize your exposure
to used oil, wear a long sleeve shirt and moisture-proof
gloves when changing oil. If oil contacts your skin, wash
Page 969 of 1501
thoroughly with soap and water.
CAUTION: Never use non-detergent or straight mineral oil.
FUEL SYSTEM SERVICE
WARNING: Relieve fuel system pressure prior to servicing any fuel
system component (fuel injection models).
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if
overheated. DO NOT touch glass portion of bulb with bare hands. Eye
protection should be worn when handling or working around halogen
bulbs.
RADIATOR CAP
CAUTION: Always disconnect the fan motor when working near the
radiator fan. The fan is temperature controlled and could
start at any time even when the ignition key is in the OFF
position. DO NOT loosen or remove radiator cap when cooling
system is hot.
RADIATOR FAN
WARNING: Keep hands away from radiator fan. Fan is controlled by a
thermostatic switch which may come on or run for up to 15 minutes even
after engine is turned off.
WARRANTY INFORMATION
CAUTION: Due to the different warranties offered in various regions
and the variety of after-market extended warranties
available, please refer to the warranty package that came
with the vehicle to verify all warranty options.
FUSES & CIRCUIT BREAKERS
FUSE PANEL LOCATION
The electrical system is protected against shorts by fuses
that are designed to fail, to prevent damage to the wire harness. The
fuse block is located under the instrument panel on the driver's side.
If a fuse is blown, locate the cause before replacing the fuse. Spare
fuses are contained in the fuse block.
FUSE PANEL IDENTIFICATION
Fuse & Circuit Breaker Identification
PASSENGER COMPARTMENT
Page 1372 of 1501
Engine overheated See ENGINE COOLING
SYSTEM article
Engine oil too heavy Check that proper
viscosity oil
is used
Poor battery-to-starter Check that all
connections between
battery and starter are
clean and tight
Current draw too low or See Bench Tests in
too high STARTER article
Bent armature, loose pole See STARTER article
shoes screws or worn
bearings
Burned solenoid contacts Replace solenoid
Faulty starter Replace starter
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Starter Engages Engine timing too far See Ignition Timing in
Engine Only advanced TUNE-UP article
Momentarily
Overrunning clutch not Replace overrunning
engaging properly clutch. See STARTER
article
Broken starter clutch See STARTER article
Broken teeth on engine Replace flywheel and
flywheel check starter pinion
gear for damage
Weak drive assembly See STARTER article
thrust spring
Weak hold-in coil See Bench Tests in
STARTER article
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Starter Drive Defective point assembly See Testing in STARTER
Will Not Engage article
Poor point assembly ground See Testing in STARTER
article
Defective pull-in coil Replace starter
solenoid
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Starter Relay Dead battery Charge or replace
Does Not Close battery as necessary
Faulty wiring Check all wiring and
connections leading to
relay
Neutral safety switch Replace neutral safety
faulty switch
Starter relay faulty Replace starter relay
Page 1378 of 1501
Parking Brake cables frozen See DRUM BRAKES
BRAKE SYSTEM
Incorrect installation of
inboard disc pad Remove and replace
correctly
Power booster output
rod too long See POWER BRAKE UNITS
BRAKE SYSTEM
Brake pedal not returning See DISC, DRUM BRAKES
freely BRAKE SYSTEM
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Brakes Grab or
Uneven Braking
Action Malfunction of combination See CONTROL VALVE or
valve BRAKE SYSTEM
Malfunction of power brake See POWER BRAKE UNITS
unit or BRAKE SYSTEM
Binding brake pedal See DISC, DRUM BRAKES
or BRAKE SYSTEM
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Pulsation or
Roughness Uneven pad wear caused by See DISC BRAKES or
caliper BRAKE SYSTEM
Uneven rotor wear See DISC BRAKES or
BRAKE SYSTEM
Drums out-of-round Reface or replace drums
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ENGINE MECHANICAL
COOLING SYSTEM TROUBLE SHOOTING
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing.
COOLING SYSTEM TROUBLE SHOOTING
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CONDITION POSSIBLE CAUSE CORRECTION \
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Overheating Coolant Leak Fill/Pressure Test
System
A/C Condenser Fins Clogged Remove/Clean Condenser
Radiator Fins Clogged Remove/Clean Radiator
Thermostat Stuck Closed Replace Thermostat
Clogged Cooling System
Passages Clean/Flush Cooling
System
Page 1380 of 1501
in the section(s) you are accessing.
BASIC GASOLINE ENGINE - MECHANICAL TROUBLE SHOOTING CHART
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CONDITION POSSIBLE CAUSE CORRECTION \
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Engine Lopes At Intake manifold-to-head Replace manifold
Idle leaks gasket, See ENGINES
Blown head gasket Replace head gasket,
See ENGINES
Worn timing gears, chain Replace gears, chain or
or sprocket sprocket
Worn camshaft lobes Replace camshaft, See
ENGINES
Overheated engine Check cooling system,
See COOLING
Blocked crankcase vent Remove restriction
valve
Leaking EGR valve Repair leak and/or
replace valve
Faulty fuel pump Replace fuel pump
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Engine Has Low Leaking fuel pump Repair leak and/or
Power replace fuel pump
Excessive piston-to-bore Install larger pistons,
clearance See ENGINES
Sticking valves or weak Check valve train
valve springs components, See ENGINES
Incorrect valve timing Reset valve timing, See
ENGINES
Worn camshaft lobes Replace camshaft, See
ENGINES
Blown head gasket Replace head gasket.
See ENGINES.
Clutch slipping Adjust pedal and/or
replace components, See
ENGINES
Engine overheating Check cooling system,
See COOLING
Auto. Trans. pressure
regulator valve faulty Replace pressure
regulator valve
Auto. Trans. fluid level Add fluid as necessary
too low
Improper vacuum diverter
valve operation Replace vacuum diverter
valve
Vacuum leaks Inspect vacuum system
and repair as required
Leaking piston rings Replace piston rings,
See ENGINES
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Faulty High Low fuel pump volume Replace fuel pump
Speed Operation
Leaking valves or worn Replace valves and/or
springs, See ENGINES
Incorrect valve timing Reset valve timing,See
ENGINES
Intake manifold restricted Remove restriction
Worn distributor shaft Replace distributor
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Faulty Improper fuel pump stroke Remove pump and reset
Acceleration pump stroke
Page 1384 of 1501
Missing valve lock Install new valve lock
Excessively worn camshaft Replace camshaft, See
lobes ENGINES
Plugged valve lifter oil Eliminate restriction
holes or replace lifter
Faulty valve lifter check Replace lifter check
ball ball, See ENGINES
Rocker arm nut installed Remove and reinstall
upside down correctly
Valve lifter incorrect for Remove and replace
engine valve lifters
Faulty push rod seat or Replace plunger or push
lifter plunger rod
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Noisy Valves Improper valve lash Re-adjust valve lash,
See ENGINES
Worn or dirty valve lifters Clean and/or replace
lifters
Worn valve guides Replace valve guides,
See ENGINES
Excessive valve seat or Reface seats or valve
face run-out face
Worn camshaft lobes Replace camshaft, See
ENGINES
Loose rocker arm studs Re-tighten rocker arm
studs, See ENGINES
Bent push rods Replace push rods, See
ENGINES
Broken valve springs Replace valve springs,
See ENGINES
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Burned,Sticking Weak valve springs or Replace valves and/or
or Broken Valves warped valves springs, See ENGINES
Improper lifter clearance Re-adjust clearance or
replace lifters
Worn guides or improper Replace valve guides,
guide clearance See ENGINES
Out-of-round valve seats Re-grind valve seats
or improper seat width
Gum deposits on valve Remove deposits
stems, seats or guides
Improper spark timing Re-adjust spark timing
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Broken Undersize pistons Replace with larger
Pistons/Rings pistons, See ENGINES
Wrong piston rings Replace with correct
rings, See ENGINES
Out-of-round cylinder bore Re-bore cylinder bore
Improper connecting rod Remove and realign
alignment connecting rods
Excessively worn ring Replace pistons, See
grooves ENGINES
Improperly assembled Re-assemble pin-to
piston pins -piston, See ENGINES
Insufficient ring gap Install new rings, See
clearance ENGINES
Engine overheating Check cooling system
Incorrect ignition timing Re-adjust ignition
timing, See TUNE-UP
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Excessive Leaks at manifold to Replace manifold or
Exhaust Noise head, or to pipe pipe gasket
Exhaust manifold Replace exhaust
Page 1390 of 1501
Incorrect injector pump Check pressure, see
housing pressure FUEL SYSTEMS
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Engine Cooling system leaks Check cooling system
Overheating and repair leaks
Belt slipping or damaged Check tension and/or
replace belt
Thermostat stuck closed Remove and replace
thermostat, see
ENGINE COOLING
Head gasket leaking Replace head gasket
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Oil Light on at Low oil pump pressure Check oil pump
Idle operation, see ENGINES
Oil cooler or line Remove restriction
restricted and/or replace cooler
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Engine Won't Injector pump fuel solenoid Remove and check
Shut Off does not return fuel valve solenoid and replace
to OFF position if needed
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VACUUM PUMP DIAGNOSIS
Excessive Noise Loose pump-to-drive Tighten screws
assembly screws
Loose tube on pump assembly Tighten tube
Valves not functioning Replace valves
properly
Oil Leakage Loose end plug Tighten end plug
Bad seal crimp Remove and re-crimp
seal
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FUEL INJECTION TROUBLE SHOOTING
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing.
BASIC FUEL INJECTION TROUBLE SHOOTING CHART
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CONDITION POSSIBLE CAUSE CORRECTION \
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Engine Won't Cold start valve inoperative Test valve and
Start (Cranks circuit
Normally)
Poor connection;vacuum or Check vacuum and
wiring electrical
connections
Contaminated fuel Test fuel for water
or alcohol
Defective fuel pump relay Test relay and
or circuit wiring
Battery too low Charge and test
battery
Page 1392 of 1501
or alcohol
Intermittent ECM ground Test ECM ground
connection for
resistance
Restricted air cleaner Replace air cleaner
Restricted exhaust system Test for exhaust
manifold back
pressure
Poor MAF sensor signal Check leakage
between sensor and
manifold
Poor VSS signal If tester for ALCL
hook-up is available
check that VSS
reading matches
speedometer
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Ping or Knock on Poor Knock sensor signal Test for shorted or
Acceleration open sensor or
circuit
Poor Baro sensor signal Test for shorted or
open sensor or
circuit
Improper ignition timing See VEHICLE EMISSION
CONTROL LABEL (where
applicable)
Check for engine Low coolant, loose
overheating problems belts or electric
cooling fan
inoperative
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NOTE: For additional electronic fuel injection trouble shooting
information, see the appropriate article in the ENGINE
PERFORMANCE section (not all vehicles have Computer Engine
Control articles). Information is provided there for
diagnosing fuel system problems on vehicles with electronic
fuel injection.
IGNITION SYSTEM TROUBLE SHOOTING
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing.
Ignition Secondary Trouble Shooting Chart
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START: Visually inspect Spark Plug Wires, Coil Wires,
Plug Wire Boots, Rotor, and Distributor Cap for
signs of damage.