
GENERAL – How to Use This Manual00-4
EXPLANATION OF MANUAL CONTENTS
Indicates procedures to be performed
before the work in that section is started,
and procedures to be performed after
the work in that section is finished.
Indicates (by symbols) where lubrica-
tion is necessary.
Maintenance and Servicing Procedures
The numbers provided within the diagram indi-
cate the sequence for maintenance and servic-
ing procedures.
Removal steps:
The part designation number corresponds
to the number in the illustration to indicate
removal steps.
Disassembly steps:
The part designation number corresponds
to the number in the illustration to indicate
disassembly steps.Installation steps:
Specified in case installation is impossible
in reverse order of removal steps. Omitted
if installation is possible in reverse order of
removal steps.
Reassembly steps:
Specified in case reassembly is impossible
in reverse order of disassembly steps.
Omitted if reassemby is possible in reverse
order of disassembly steps.
Classifications of Major Maintenance/Service Points
When there are major points relative to maintenance and servicing procedures
(such as essential maintenance and service points, maintenance and service stan-
dard values, information regarding the use of special tools, etc.), these are ar-
ranged together as major maintenance and service points and explained in detail.
A: Indicates that there are essential points for removal or disassembly.
A: Indicates that there are essential points for installation or reassembly.
Symbols for Lubrication, Sealants and Adhesives
Information concerning the locations for lubrica-
tion and for application of sealants and adhe-
sives is provided, by using symbols, in the dia-
gram of component parts or on the page follow-
ing the component parts page, and explained.: Grease
(multipurpose grease unless there is a
brand or type specified)
: Sealant or adhesive
: Brake fluid or automatic transmission fluid
: Engine oil, gear oil or air conditioner com-
pressor oil
: Adhesive tape or butyl rubber tape
Component Diagram
A diagram of the component parts is
provided near the front of each section
in order to give a reader a better under-
standing of the installed condition of
component parts.

ENGINE – General Information11-2
GENERAL INFORMATION
DescriptionsSpecifications
TypeIn-line OHV, SOHC
Number of cylinders4
Combustion chamberPentroof + curved top piston type
Total displacement dm31,997
Cylinder bore mm85.0
Piston stroke mm88.0
Compression ratio8.8
Valve timingIntake valveOpens (BTDC)21°
Closes (ABDC)59°
Exhaust valveOpens (BBDC)58°
Closes (ATDC)18°
Lubrication systemPressure feed, full-flow filtration
Oil pump typeInvolute gear type

ENGINE – Specifications11-9
NEW TIGHTENING METHOD – BY USE OF BOLTS TO BE TIGHTENED IN
PLASTIC AREA
A new type of bolts, to be tightened in plastic area, is currently used some parts of the engine. The
tightening method for the bolts is different from the conventional one. Be sure to observe the method
described in the text when tightening the bolts.
Service limits are provided for the bolts. Make sure that the service limits described in the text are strictly
observed.
Areas where the bolts are in use:
(1) Cylinder head bolts
(2) Main bearing cap bolts
(3) Connecting rod cap bolts
Tightening method
After tightening the bolts to the specified torque, tighten them another 90° or 180° (twice 90°). The
tightening method varies on different areas. Observe the tightening method described in the text.
SEALANTS
ItemSpecified sealantQuantity
Engine support bracket bolt3MTM AAD Part No. 8672 or equivalentAs required
Semi-circular packing3MTM AAD Part No. 8672 or equivalentAs required
Rocker cover3MTM AAD Part No. 8672 or equivalentAs required
Oil return pipe gasket3MTM AAD Part No. 8731 or equivalentAs required
Thermostat housingMitsubishi Genuine Part No. MD970389 or
equivalentAs required
Water outlet fittingMitsubishi Genuine Part No. MD970389 or
equivalentAs required
Engine coolant temperature gauge unit3MTM AAD Part No. 8672 or equivalentAs required
Engine coolant temperature sensor3MTM AAD Part No. 8731 or equivalentAs required
Cam position sensor supportMitsubishi Genuine Part No. MD970389 or
equivalentAs required
Oil pressure switch3MTM AAD Part No. 8672 or equivalentAs required
Oil panMitsubishi Genuine Part No. MD970389 or
equivalentAs required
Oil seal caseMitsubishi Genuine Part No. MD970389 or
equivalentAs required

ENGINE – Specifications11-10
FORM-IN-PLACE GASKET
The engine has several areas where the form-in-place gasket (FIPG) is in use. To ensure that the gasket
fully serves its purpose, it is necessary to observe some precautions when applying the gasket. Bead
size, continuity and location are of paramount importance. Too thin a bead could cause leaks. Too thick
a bead, on the other hand, could be squeezed out of location, causing blocking or narrowing of the
fluid feed line. To eliminate the possibility of leaks from a joint, therefore, it is absolutely necessary to
apply the gasket evenly without a break, while observing the correct bead size.
The FIPG used in the engine is a room temperature vulcanisation (RTV) type and is supplied in a 100-gram
tube (Part No. MD970389). Since the RTV hardens as it reacts with the moisture in the atmospheric
air, it is normally used in the metallic flange areas. The FIPG, Part No. MD970389, can be used for
sealing both engine oil and coolant, while Part No. MD997110 can only be used for engine oil sealing.
Disassembly
The parts assembled with the FIPG can be easily disassembled without use of a special method. In
some cases, however, the sealant between the joined surfaces may have to be broken by lightly striking
with a mallet or similar tool. A flat and thin gasket scraper may be lightly hammered in between the
joined surfaces. In this case, however, care must be taken to prevent damage to the joined surfaces.
For removal of the oil pan, the special tool “Oil Pan Remover” (MD998727) is available. Be sure to use
the special tool to remove the oil pan.
Surface Preparation
Thoroughly remove all substances deposited on the gasket application surfaces, using a gasket scraper
or wire brush. Check to ensure that the surfaces to which the FIPG is to be applied is flat. Make sure
that there are no oils, greases and foreign substances deposited on the application surfaces. Do not
forget to remove the old sealant remained in the bolt holes.
Form-in-Place Gasket Application
When assembling parts with the FIPG, you must observe some precautions, but the procedures is very
simple as in the case of a conventional precut gasket.
Applied FIPG bead should be of the specified size and without breaks. Also be sure to encircle the
bolt hole circumference with a completely continuous bead. The FIPG can be wiped away unless it is
hardened. While the FIPG is still moist (in less than 15 minutes), mount the parts in position. When
the parts are mounted, make sure that the gasket is applied to the required area only. In addition, do
not apply any oil or water to the sealing locations or start the engine until a sufficient amount of time
(about one hour) has passed after installation is completed.
The FIPG application procedure may vary on different areas. Observe the procedure described in the
text when applying the FIPG.

ENGINE – Front Case, Counterbalance Shaft and Oil Pan11-58
COUNTERBALANCE SHAFT
(1) Check oil holes for clogging.
(2) Check journals for seizure, damage and contact with
bearing. If there is anything wrong with the journal, replace
the counterbalance shaft, bearing or front case assembly.
OIL COOLER BY-PASS VALVE (ENGINE WITH AIR
COOLING TYPE OIL COOLER)
(1) Make sure that the valve moves smoothly.
(2) Ensure that the dimension (L) measures the standard
valve under normal temperature and humidity.
Standard value (L): 34.5 mm
(3) The dimension must be the standard value when
measured after the valve has been dipped in 100°C oil.
Standard value (L): 40 mm or more
OIL PUMP
(1) Assemble the oil pump gear to the front case and rotate
it to ensure smooth rotation with no looseness.
(2) Ensure that there is no ridge wear on the contact surface
between the front case and the gear surface of the oil
pump cover.
(3) Check the side clearance.
Standard value:
Drive gear 0.08 – 0.14 mm
Driven gear 0.06 – 0.12 mm
Valve

ENGINE – Turbocharger11-78
COMPRESSOR COVER
Check the compressor cover for traces of contact with the
compressor wheel and other damage.
TURBINE WHEEL ASSEMBLY
(1) Check the turbine and compressor wheel blades for bend,
burr, damage, corrosion and traces of contact on the
back side and replace if defective.
(2) Check the oil passage of the turbine wheel assembly
for deposit and clogging.
(3) In the case of water cooled type, check also the water
passage for deposit and clogging.
(4) Check the turbine wheel and compressor wheel for light
and smooth turning.Oil passage
Turbine wheel
Compressor
wheelWater passage