1991 MITSUBISHI MONTERO cooling

* Wrap shop towels around fuel return and high pressure hoses
to prevent fuel splashing on engine. Disconnect fuel return
hose and high pressure fuel hose to drain any residual fuel.
ENGINE
Removal (Montero & Pickup)
1) Remove hood. Drain cooling system, and remove radiator.
Remove skid plate and splash shields. Release fuel system pressure.
See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect
negative battery cable.
2) Remove air cleaner ducts. Remove accessory drive belts.
Remove and support A/C compressor and power steering pump. DO NOT
disconnect hoses from compressor or pump. Disconnect oil cooler hoses.
Cover fuel hose using shop towel, and disconnect high pressure fuel
hose and "O" ring. Remove fuel return hose.
3) Label and disconnect all vacuum hoses. Disconnect cooling
system hoses. Label and disconnect all electrical connections from
engine. Remove heat shield from motor mounts. Remove motor mount
bolts. Ensure all hoses and wires are disconnected and set aside.
4) Disconnect exhaust pipe from exhaust manifolds. Remove
starter. Attach engine hoist to engine. Support transmission.
Disconnect engine from transmission. See appropriate article in
CLUTCHES or TRANSMISSION SERVICING. Remove engine.
Installation (Montero & Pickup)
To install, reverse removal procedure. Install new "O" ring
on fuel line. Install new exhaust gaskets and nuts. See TORQUE
SPECIFICATIONS (MONTERO & PICKUP) table at end of article. Adjust
fluid levels.
Removal (3000GT)
1) Release fuel pressure. See FUEL PRESSURE RELEASE under
REMOVAL & INSTALLATION. Remove hood. Remove cruise control vacuum pump
and linkage. On turbo models, remove necessary turbo air intake hoses
and pipes. On all other models, remove air cleaner hoses.
2) On all models, drain cooling system. Drain engine oil and
transaxle oil. Remove heater hoses and radiator hoses. Remove
transaxle assembly. See appropriate article in CLUTCHES or
TRANSMISSION SERVICING.
3) Remove radiator. Label and disconnect all vacuum hoses.
Label and disconnect all electrical connections and harnesses from
engine. Remove accessory drive belts.
4) Remove and support A/C compressor and power steering pump.
DO NOT disconnect hoses from compressor or pump. Cover fuel hose using
shop towel, and disconnect high pressure fuel hose and "O" ring.
Remove fuel return hose.
5) On turbo models, disconnect oil cooler and vacuum hoses.
On all models, remove motor mount bolts and brackets. Ensure all hoses
and wires are disconnected and set aside. Attach engine hoist to
engine. Remove engine.
Installation
To install, reverse removal procedure. Install new "O" ring
on fuel line. Install new exhaust gaskets and nuts. See TORQUE
SPECIFICATIONS (3000GT) table at end of article. Adjust fluid levels.
UPPER INTAKE MANIFOLD
Removal (Montero & Pickup)
1) Remove air intake hose. See Fig. 1. Remove accelerator
cable adjusting bolts. On models equipped with automatic transmission,
remove throttle control cable. On all models, remove accelerator

released before disconnecting fuel lines.
Removal
1) Release fuel pressure. See FUEL PRESSURE RELEASE under
REMOVAL & INSTALLATION. Remove upper intake manifold. See UPPER INTAKE
MANIFOLD under REMOVAL & INSTALLATION.
2) Drain cooling system. Remove high pressure and return fuel
lines. Cover fuel lines using shop towel during removal as some fuel
may be retained. Remove vacuum hose from pressure regulator.
Disconnect injector harness from injectors.
3) Remove fuel delivery pipe, fuel injectors and pressure
regulator. See Fig. 3. DO NOT allow injectors to fall from delivery
pipe during removal. Remove vacuum hose and pipe assembly.
4) On Montero & Pickup, disconnect coolant temperature
sending unit, coolant temperature switch (A/C equipped), coolant
temperature sensor and thermoswitch (A/T equipped). Disconnect upper
radiator and coolant by-pass hoses. Disconnect heater pipe. On all
models, remove intake manifold and gasket.
Fig. 3: Exploded View of Lower Intake Manifold & Components
Courtesy of Mitsubishi Motor Sales of America, Inc.
Inspection & Installation
1) Inspect for damage and cracks on all mounting surfaces. To

Removal (SOHC)
1) Drain cooling system. Remove upper and lower intake
manifolds and brackets. See UPPER INTAKE MANIFOLD and LOWER INTAKE
MANIFOLD under REMOVAL & INSTALLATION. Remove spark plug wires. Remove
splash shields.
2) Disconnect O2 sensor. Disconnect exhaust pipe from exhaust
manifold, and support to crossmember using wire. Remove heat shields
and exhaust manifolds. See EXHAUST MANIFOLDS under REMOVAL &
INSTALLATION.
3) Remove distributor (left or rear head). Remove timing bel\
t
outer covers, camshaft sprockets, timing belt and timing belt inner
covers. See TIMING BELT under REMOVAL & INSTALLATION. Remove accessory
bracket bolts from front of cylinder head. Remove rocker cover and
gasket.
4) Using Socket (MD998051), loosen cylinder head bolts in 2-\
3
steps using proper sequence. See Fig. 5. Remove cylinder head and
camshaft assemblies. Note direction of washer installation on head
bolts.
NOTE: Cylinder head bolts must be loosened in 2-3 steps using
proper sequence to prevent cylinder head warpage and
cracking.
Fig. 5: Cylinder Head Bolt Removal & Tightening Sequence
Courtesy of Mitsubishi Motor Sales of America, Inc.
Inspection (SOHC)
Check cylinder head height and warpage at gasket and manifold

surfaces. Resurface head if warpage exceeds specification. See
CYLINDER HEAD (SOHC) table under ENGINE SPECIFICATIONS at end of
article. Replace cylinder head if it is not within specification after
resurfacing.
Installation (SOHC)
1) Ensure mating surfaces are clean and dry. Note
identification mark located on front of head gasket. Identification
marks are: "R" for SOHC, "2DN" for DOHC non-turbocharged and "2DT" for
DOHC turbocharged engine. Install head gasket with identification mark
toward timing belt side of engine and facing upward. Ensure all holes
are aligned.
NOTE: Install head gasket with identification mark toward timing
belt side of engine and facing upward. Ensure all holes
align. Install washers on head bolts with chamfered side
toward bolt head.
2) Install cylinder head and bolts. Ensure washers are
installed on head bolts with chamfered side toward bolt head. Using
proper sequence, tighten bolts to specification in 2-3 steps. See
Fig. 5 . See appropriate TORQUE SPECIFICATIONS table at end of article.
3) Apply sealant to rocker cover sealing surfaces before
installation. See Fig. 6. Ensure rocker cover gasket projections are
aligned with notches in rocker cover. Coat all "O" rings with oil, and
install a new "O" ring on distributor adapter and oil dipstick tube.
4) Coat camshaft area with oil prior to installing
distributor adapter. To complete installation, reverse removal
procedure. Tighten bolts and nuts to specification. See appropriate
TORQUE SPECIFICATIONS table. After engine reaches normal operating
temperature, allow engine to cool, and retighten cylinder head bolts.
Fig. 6: Applying Sealant to Rocker Cover (SOHC)
Courtesy of Mitsubishi Motor Sales of America, Inc.
Removal (DOHC)
1) Drain cooling system. Remove upper and lower intake
manifolds and brackets. See UPPER INTAKE MANIFOLD and LOWER INTAKE
MANIFOLD under REMOVAL & INSTALLATION.
2) Remove turbocharger(s) (if equipped). See TURBOCHARGER
under REMOVAL & INSTALLATION. Remove heat shields from exhaust
manifolds. Remove exhaust manifolds. See EXHAUST MANIFOLDS under
REMOVAL & INSTALLATION.
3) Remove spark plug wires and ignition coils. Remove rocker
cover and gasket. Remove timing belt and timing belt inner covers. See

TIMING BELT under REMOVAL & INSTALLATION. Remove intake camshaft
sprockets.
4) Remove coolant manifold and coolant inlet pipe. Using
Socket (MD998051), remove cylinder head bolts. Remove cylinder head
and camshaft assemblies. Note direction of washer installation on head
bolts.
Inspection (DOHC)
Check cylinder head height. Check warpage at gasket and
manifold surfaces. Resurface head if warpage exceeds specification.
See CYLINDER HEAD (DOHC) table under ENGINE SPECIFICATIONS at end of
article. After resurfacing, recheck cylinder head height. Replace
cylinder head if it is not within specification.
Installation (DOHC)
1) Ensure mating surfaces are clean and dry. Note
identification mark located on front of head gasket. Identification
marks are: "R" for SOHC, "2DN" for DOHC non-turbocharged and "2DT" for
DOHC turbocharged engine. Install head gasket with identification mark
toward timing belt side of engine and facing upward. Ensure all holes
are aligned.
NOTE: Install head gasket with identification mark toward timing
belt side of engine and facing upward. Ensure all holes
align. Install washers on head bolts with chamfered side
toward bolt head.
2) Install cylinder head and bolts. Ensure washers are
installed on head bolts with chamfered side toward bolt head. Using
proper sequence, tighten bolts to specification in 2-3 steps. See
Fig. 5 . See TORQUE SPECIFICATIONS (3000GT) table at end of article. On
turbocharger equipped engines, back off head bolts once, and repeat
tightening procedure.
3) To reinstall camshaft sprocket, hold hexagonal area of
camshaft using wrench while tightening sprocket bolt. Tighten rocker
cover bolts in a crisscross pattern. Start at 4 corners of rocker
cover and move toward center.
NOTE: Rocker cover bolts are color coded. Front cylinder bank
bolts are black; rear cylinder bank bolts are green.
4) To complete installation, reverse removal procedure.
Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS
(3000GT) table.
FRONT CRANKSHAFT OIL SEAL
Removal & Installation
Remove timing belt and crankshaft sprocket. See TIMING BELT
under REMOVAL & INSTALLATION. Pry oil seal from oil pump. To install,
coat seal lip with grease. Using Seal Installer (MD998717), install
seal in oil pump. Install remaining components. See appropriate TORQUE
SPECIFICATIONS table at end of article.
TIMING BELT
Removal (Montero & Pickup)
1) Drain cooling system. Disconnect upper radiator hose.
Remove upper radiator shroud. Remove cooling fan and fan clutch
assembly. Remove cooling fan pulley. Remove all drive belts. Remove
power steering pump with pressure and return hoses connected, and set
aside.
2) Remove power steering pump brackets. Remove A/C tensioner

pulley and mounting bracket. Remove A/C compressor with hoses
connected, and remove mounting bracket. Remove cooling fan bracket
assembly. Note location and length of bolts for reassembly reference.
3) Remove No. 1 and No. 2 timing belt upper outer covers and
gaskets. See Fig. 7. Remove timing belt lower outer cover and gaskets.
Using Holder (MB998747) and a used "V" belt, remove crankshaft pulley
bolt. Remove crankshaft pulley.
NOTE: "V" belt will be damaged by tool. DO NOT use engine "V"
belt to hold crankshaft pulley unless replacing belt.
4) Remove flange. See Fig. 7. Rotate crankshaft and align all
timing marks. See Fig. 8. Loosen belt tensioner bolt, and rotate belt
tensioner counterclockwise to release belt tension.
5) If reusing timing belt, place arrow on belt to indicate
direction of belt rotation. Remove timing belt and belt tensioner. If
camshaft sprocket requires removal, install Holder (MB990775) on
camshaft sprocket. Remove retaining bolt and camshaft sprocket. Remove
rear timing belt cover (if required).
Fig. 7: Exploded View of Timing Belt Components (SOHC Is Similar)
Courtesy of Mitsubishi Motor Sales of America, Inc.

and No. 2. Install bearing caps with front mark arrow facing the same
direction as similar mark on cylinder head beside bearing journal.
Note bearing cap number and identification mark ("I" for intake
camshaft and "E" for exhaust). See Fig. 22.
3) Install front and rear bearing caps. Tighten bearing cap
bolts to specification. See TORQUE SPECIFICATIONS (3000GT) table at
end of article. Coat camshaft oil seal area with oil. Using Seal
Installer (MD998761), install camshaft oil seal. Using Circular
Packing Installer (MD998761), install circular packing.
4) Install crankshaft angle sensor adapter. To complete
installation, reverse removal procedure. Tighten bolts to
specification. See TORQUE SPECIFICATIONS table.
REAR CRANKSHAFT OIL SEAL
Removal
Remove transaxle/transmission. See appropriate article in
TRANSMISSION SERVICING or CLUTCHES. Remove flywheel or drive plate.
Remove rear oil seal case. Pry seal from seal case.
Installation
To install, coat seal lip with oil. Using Seal Installer
(MD998718), install seal in seal case. Apply sealant to sealing
surface of seal case. Install seal case. Install flywheel or drive
plate. Tighten bolts to specification. See appropriate TORQUE
SPECIFICATIONS table at end of article. To complete installation,
reverse removal procedure.
WATER PUMP
Removal
Drain cooling system. Remove timing belt and crankshaft
sprocket. See TIMING BELT under REMOVAL & INSTALLATION. Remove coolant
pipes to water pump (if required). Remove water pump bolts, noting
length and location for reassembly reference. Remove water pump.
Installation
To install, reverse removal procedure using new gasket and
"O" rings. Coat all "O" rings with water before installation. Install
water pump and gasket. Tighten bolts to specification. See appropriate
TORQUE SPECIFICATIONS table at end of article.
OIL PAN
Removal (Montero)
1) Remove hood. Remove skid plate and lower covers. Raise and
support vehicle. Disconnect and remove exhaust pipe from exhaust
manifolds. Drain engine oil. Remove starter cover and starter. Remove
oil pressure sending unit connector. Remove front suspension
crossmember.
2) Remove transmission stays. Remove ground cable and motor
mount heat shields. Attach engine hoist. Remove motor mount bolts.
Raise engine, and insert a 1" wood spacer between front insulator and
mounts. Lower engine onto wood blocks.
3) Raise vehicle using a hoist. Remove oil pan bolts. Using
Seal Cutter (MD998727), separate oil pan from cylinder block. Remove
pan from vehicle.
Removal (Pickup)
1) Remove skid plate and lower covers. Raise and support
vehicle. Drain engine oil. Using Steering Linkage Puller (C-3894-A or
MB990635), disconnect relay rod from idler arm and steering box.
2) Remove oil pan bolts. Using Seal Cutter (MD998727),

and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when
connecting lines or fittings. Dip "O" ring in new refrigerant oil and
ensure it is not twisted during installation. Always use 2 wrenches to
prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and
all connections have been made, evacuate system thoroughly with a
vacuum pump. Charge system with proper amount of refrigerant and
perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart
in this section for system capacities. Be sure to check all fittings
that have been opened. After system has been leak tested, make a
system performance check.
NOTE: Air conditioning systems will not normally need addition of
refrigerant oil unless definite oil loss has occurred due to
ruptured lines, leaking compressor seals, compressor
overhaul or component replacement.
ATSUGI ROTARY VANE DRAIN & REFILL
1) Before checking and adjusting oil level, operate
compressor at engine idling speed, with controls set for maximum
cooling and high blower speed, for 20 to 30 minutes to return oil to
compressor.
2) Stop engine, discharge refrigerant and remove compressor
from vehicle. See SERVICING PRECAUTIONS at beginning of article. Drain
compressor oil from compressor discharge port and measure the amount.
Oil is sometimes hard to drain when compressor is cool. Remove oil
while compressor is warm.
3) If the amount drained is less than 3 ounces, conduct leak
tests at system connections, and if necessary, repair or replace
faulty parts. Check purity of oil and adjust oil level as follows.
4) If amount drained was above 3 ounces, oil level is right.
Pour in same amount as was drained. If amount drained was below 3
ounces, pour in 3 ounces of new refrigerant oil.
BOSCH 6-CYL DRAIN & REFILL
1) Before checking and adjusting oil level, operate
compressor at engine idling speed, with controls set for maximum
cooling and high blower speed, for 20 to 30 minutes to return oil to
compressor.
2) Stop engine and discharge refrigerant. Remove refrigerant
oil level inspection plug on side of compressor. Oil should be at
lower lip of threaded hole. Add necessary new refrigerant oil (if
low). Replace inspection plug and tighten to 10-12 ft. lbs. (14-16 N.
m).
CALSONIC V5 5-CYLINDER
1) Before checking and adjusting oil level, operate
compressor at 1000-1500 engine RPM, and set controls at maximum
cooling and blowing speed for 20-30 minutes to return oil to