1998 MITSUBISHI MONTERO Service Manual

GENERAL COOLING SYSTEM SERVICING
1998 Mitsubishi Montero
GENERAL INFORMATION
General Cooling System Servicing
* PLEASE READ THIS FIRST *
The following article is for general information only.
Information may not apply to all years, makes and models. See specific
article in the ENGINE COOLING section.
DESCRIPTION
The basic liquid cooling system consists of a radiator, water
pump, thermostat, electric or belt-driven cooling fan, pressure cap,
heater, and various connecting hoses and cooling passages in the block
and cylinder head.
MAINTENANCE
DRAINING
Remove radiator cap and open heater control valve to maximum
heat position. Open drain cocks or remove plugs in bottom of radiator
and engine block. In-line engines usually have one plug or drain cock,
while "V" type engines will have 2, one in each bank of cylinders.
CLEANING
A good cleaning compound removes most rust and scale. Follow
manufacturer's instructions in the use of cleaner. If considerable
rust and scale has to be removed, cooling system should be flushed.
Clean radiator air passages with compressed air.
FLUSHING
CAUTION: Some manufacturers use an aluminum and plastic radiator.
Flushing solution must be compatible with aluminum.
Back Flushing
Back flushing is an effective means of removing cooling
system rust and scale. The radiator, engine and heater core should be
flushed separately.
Radiator
To flush radiator, connect flushing gun to water outlet of
radiator and disconnect water inlet hose. To prevent flooding engine,
use a hose connected to radiator inlet. Use air in short bursts to
prevent damage to radiator. Continue flushing until water runs clear.
Engine
To flush engine, remove thermostat and replace housing.
Connect flushing gun to water outlet of engine. Flush using short air
bursts until water runs clean.
Heater Core
Flush heater core as described for radiator. Ensure heater
control valve is set to maximum heat position before flushing heater.

REFILLING
To prevent air from being trapped in engine block, engine
should be running when refilling cooling system. After system is full,
continue running engine until thermostat is open, then recheck fill
level. Do not overfill system.
TESTING
THERMOSTAT
1) Visually inspect thermostat for corrosion and proper
sealing of valve and seat. If okay, suspend thermostat and thermometer
in a 50/50 mixture of coolant and water. See Fig. 1. Do not allow
thermostat or thermometer to touch bottom of container. Heat water
until thermostat just begins to open.
2) Read temperature on thermometer. This is the initial
opening temperature and should be within specification. Continue
heating water until thermostat is fully open and note temperature.
This is the fully opened temperature. If either reading is not to
specification, replace thermostat.
Fig. 1: Testing Thermostat in Anti-Freeze/Water Solution
PRESSURE TESTING
A pressure tester is used to check both radiator cap and

complete cooling system. Test components as follows, following tool
manufacturer's instructions.
Radiator Cap
Visually inspect radiator cap, then dip cap into water and
connect to tester. Pump tester to bring pressure to upper limit of cap
specification. If cap fails to hold pressure, replace cap.
Fig. 2: Testing Radiator Pressure Cap
Cooling System
1) With engine off, wipe radiator filler neck seat clean.
Fill radiator to correct level. Attach tester to radiator and pump
until pressure is at upper level of radiator rating.
2) If pressure drops, inspect for external leaks. If no leaks
are apparent, detach tester and run engine until normal operating
temperature is reached. Reattach tester and observe. If pressure
builds up immediately, a possible leak exists from a faulty head
gasket or crack in head or block.
NOTE: Pressure may build up quickly. Release any excess pressure
or cooling system damage may result.
3) If there is no immediate pressure build up, pump tester to
within system pressure range (on radiator cap). Vibration of gauge
pointer indicates compression or combustion leak into cooling system.
Isolate leak by shorting each spark plug wire to cylinder block. Gauge
pointer should stop or decrease vibration when leaking cylinder is
shorted.

GENERATOR & REGULATOR
1998 Mitsubishi Montero
1998 STARTING & CHARGING SYSTEMS
Mitsubishi - Generators & Regulators
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
DESCRIPTION & OPERATION
NOTE: The terms generator and alternator are interchangeable.
Mitsubishi generators are conventional 3-phase, self-
rectifying type units containing 6 diodes (3 positive and 3 negative)
which are used to rectify current. All models use a case-mounted
Integrated Circuit (IC) voltage regulator.
Generator relay or resistor with diode is used to ensure
charging of battery even if charging indicator light is defective.
ADJUSTMENTS
BELT TENSION
For belt tension, see DRIVE BELT ADJUSTMENT table.
DRIVE BELT ADJUSTMENT TABLE









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( 1) Deflection ( 1) Deflection
Application New Belt In. (mm) Used Belt In. (mm\
)
Diamante ( 2) ........... .24-.28 (6.0-7.2) ..... .32-.37 (8.2-9.3)
Eclipse
2.0L Non-Turbo ( 3) ... .30-.41 (7.5-10.5) ... .35-.47 (9.0-12.0)
2.0L Turbo ( 4) ....... .30-.35 (7.5-9.0) ............ .39 (10.0)
2.4L ( 4) ............. .30-.35 (7.5-9.0) ............ .39 (10.0)
Galant ( 4) ............. .30-.35 (7.5-9.0) ............ .39 (10.0)
Mirage ( 3)
1.5L ................. .36-.42 (9.2-10.6) .... .26-.33 (6.6-8.3\
)
1.8L ................. .33-.39 (8.5-10.0) .... .28-.31 (7.0-8.0\
)
Montero ( 4) ............ .22-.29 (5.5-7.5) ..... .31-.35 (8.0-9.0)
Montero Sport
2.4L ( 4) ............. .22-.29 (5.5-7.5) ..... .30-.33 (7.5-8.3)
3.0L ( 4) ............. .22-.29 (5.5-7.5) ..... .31-.35 (8.0-9.0)
3000GT
DOHC ( 5) ............. .14-.16 (3.5-4.0) ..... .16-.20 (4.0-5.0)
SOHC ( 6) ............. .16-.20 (4.0-5.0) ..... .24-.32 (6.0-8.0)
( 1) - With 22 lbs. (10 kg) pressure applied midway on belt run.
( 2) - Measure between A/C compressor pulley and crankshaft pulley.
( 3) - Measure between crankshaft pulley and generator pulley.
( 4) - Measure between water pump pulley and generator pulley.
( 5) - Measure between crankshaft pulley and idler pulley.
( 6) - Measure between power steering pulley and idler pulley.









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TROUBLE SHOOTING
NOTE: See TROUBLE SHOOTING article in the GENERAL INFORMATION
section.

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.

GENERATOR OUTPUT TEST
NOTE: A slightly discharged battery should be used, as a fully
charged battery may not allow full generator output.
1) Turn ignition off. Disconnect negative battery cable.
Disconnect generator output wire from terminal "B". Connect positive
lead of 100-amp ammeter to terminal "B" and negative lead to
disconnected output lead.
CAUTION: Tighten each connection securely, as heavy current flow will
exist. DO NOT use clips on ammeter. An inductive-type
ammeter is recommended.
2) Connect positive voltmeter lead (0-20 volts) to generator\
terminal "B" and negative lead to ground. Install a tachometer and
reconnect negative battery cable.
3) Ensure voltmeter indicates battery voltage. If voltage is
not present, check for open circuit in wire between generator terminal
"B" and positive battery terminal. Check grounds and fusible link.
4) Start engine and turn headlights on. Set headlights at
high beam and heater blower switch on HIGH. Increase engine speed to
2500 RPM and note generator output current on ammeter. Minimum output
should be within specification. See
GENERATOR MINIMUM OUTPUT SPECIFICATIONS table.
NOTE: Output voltage changes with electrical load and temperature.
Ensure proper electrical load is applied while checking
output. Nominal output may not be obtained if generator or
ambient temperature is excessive. Allow generator or
temperature to cool, and recheck output. Generator output is
stamped on metal plate attached to generator case.
5) If minimum output is not obtained and generator wiring is
okay, repair generator. Operate engine at idle speed after the test.
GENERATOR MINIMUM OUTPUT SPECIFICATIONS TABLE









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Application Amps
Diamante ............................................. 110
Eclipse
2.0L Non-Turbo ...................................... 90
2.0L Turbo .......................................... 75
2.4L ................................................ 90
Galant ................................................ 90
Mirage ................................................ 80
Montero .............................................. 100
Montero Sport
2.4L ................................................ 60
3.0L ................................................ 85
3000GT
DOHC ............................................... 110
SOHC ................................................ 90









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REGULATED VOLTAGE TEST
NOTE: Ensure battery is fully charged and proper drive belt
tension exists.
1) Turn ignition switch off. Disconnect negative battery
cable. Connect positive voltmeter lead to terminal "S" of generator.

See Fig. 1 . Connect negative voltmeter lead to ground.
2) Disconnect generator output wire from terminal "B".
Install a 100-amp ammeter in series with terminal "B" and disconnected
output lead. Connect positive lead of ammeter to terminal "B" and
negative lead to disconnected output wire. Install a tachometer, and
reconnect negative battery cable.
3) Turn ignition switch on and ensure voltmeter indicates
battery voltage. If voltage is not present, check for open in wire
between generator terminal "S" and positive battery terminal. Check
for blown fusible link.
4) Start engine. Ensure all lights and accessories are off.
Operate engine at 2500 RPM and read voltmeter when generator output
current drops to 10 amps or less. Voltage regulator is okay if voltage
output is within specification. See REGULATOR VOLTAGE SPECIFICATIONS
table.
REGULATOR VOLTAGE SPECIFICATIONS TABLE









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Ambient Temperature Voltage
-4
F (-20C) ................................... 14.2-15.4
68F (20C) .................................... 13.9-14.9
140F (60C) ................................... 13.4-14.6
176F (80C) ................................... 13.1-14.5








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GENERATOR RELAY TEST
NOTE: Information for all other models is not available from
manufacturer at time of publication.
Diamante & Mirage
Remove generator relay. On Diamante, relay is located in
relay box in engine compartment near battery. On Mirage, relay is
located in relay box in engine compartment between battery and strut
tower. On both models, connect positive lead of ohmmeter to relay
terminal No. 4. See WIRING DIAGRAMS. Connect negative lead of ohmmeter
to relay terminal No. 2. Continuity should be present. Switch ohmmeter
lead locations. Continuity should not be present. Replace generator
relay if continuity is not as specified.
BENCH TESTING
RECTIFIER ASSEMBLY
1) Using ohmmeter, check for continuity between diodes and
stator coil lead connection. See Fig. 2. Reverse leads. If continuity
is present in both directions, diode is shorted. Replace rectifier
assembly.
2) To check entire diode assembly, use an ohmmeter to check
for continuity between both ends of each diode. See Fig. 2. Switch
ohmmeter leads. Continuity should be present in one direction only. If
continuity is not as specified, diode is defective. Replace rectifier
assembly.

Fig. 2: Testing Rectifier Assembly
Courtesy of Mitsubishi Motor Sales of America
ROTOR