lock MITSUBISHI 3000GT 1991 User Guide

L’
LENGINE
- Specifications11-5
Items
Standard value
Limit
Cylinder head
Overall height
mm (in.)
132 (5.20)-0.2 (-,008)’
Flatness of gasket surface
mm (in.)Max. 0.03 l.0012)0.2 (.008)
Oversize rework dimension of valveseat hole
mm (in.)
Intake
0.3 f.012) O.S.36.300 - 36.325 (1.4291 - 1.4301)
0.6 l.024) O.S.36.600 - 36.625 (1.4409 - 1.4419)
Exhaust 0.3
l.012) O.S.33.300 - 33.325 (1.31 IO - 1.3120)
0.6 (.024) O.S.33.600 - 33.625 (1.3228 - 1.3238)
Oversize rework dimension of valveseat hole depth
mm (in.)
Intake
0.3 l.012) O.S.7.5 - 7.7 (.295 - ,303)
0.6 t.024) O.S.
7.8 - 8.0 (.307 - ,315)
Exhaust 0.3 t.012) O.S.7.9-8.1 (.311 - ,319)
0.6 (.024) O.S.
8.2 - 8.4 (.323 - .331)
Oversize rework of valve guide hole
(both intake and exhaust)mm (in.)
0.05 f.002) 0,s.13.050- 13.068(.5138-.5145)
0.25 (.OlO) O.S.13.250- 13.268 (.5217- .5224)
0.50 (.020) 0,s.13.500 - 13.518 (.5315 - .5322)
Samshaft
Cam heightmm (in.)
Intake
35.49 (I .3972)34.99 (1.3776)
Exhaust
35.20 (1.3858)
34.70 (1.3661)
Journal O.D.
mm (in.)
26 (1.02)
Bearing oil clearance
mm (in.)0.05 - 0.09 f.0020 - .0035)
Jalve
Valve lengthmm (in.)
Intake
106.3 (4.185)
Exhaust
105.4 (4.150)
Stem O.D.mm (in.)
Intake
6.6 (.260)
Exhaust6.6 i.260)
Face angle
45 - 45.5”Thick;;ss,yf
valve head (Margin)
Intake
1 .o (.039)0.5 (.019)
Exhaust1.5 (.059)1 .o (.039)
Clearance (Valve stem to guide)
mm (in.)
Intake
0.02 - 0.05 (.0008 - .0020)0.10 l.0039)
Exhaust0.05 - 0.09 l.0020 - .0035)0.12 i.0047)
* Limit must be -0.2 mm (--.008 in.) combined with amount of grinding of cylinder block gasket surface.
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11-6ENGINE - Specifications
Items
Valve guide
Lengthmm (in.)
Intake
Exhaust
Service sizemm (in.)Standard value
45.5 (1.791)
50.5 (1.988)
0.05 f.002). 0.25 (.OlO),0.50 f.020) OversizeLimit
Valve seat
Width of seat contactmm (in.)0.9 - 1.3 (.035 - ,051)
Seat angle44 - 44.5”
Valve spring
Free lengthmm (in.)46.9 (1.846)45.9 (1.807)
LoadN (Ibs.)280 (62) at installed height
Installed heightmm (in.)37.9 (1.492)38.9 (1.531)
Squareness1
Less than 2”4”
Cylinder block
Cylinder boremm (in.)
91 .I0
(3.5866)
Out-of-roundness and taper of cylinderLess than 0.02 i.0008)
boremm (in.)
Flatness of gasket surfacemm (in.)
Less than 0.05 t.0020)0.10 (.0039)
Piston0.D mm (in.)
91 .I0 (3.5866)
Clearance (Piston to cylinder)mm (in.)
0.03 - 0.05 (.0012 - .0020)
Ring groove widthmm (in.)
No. 11.2 (.047)
No. 21.5 f.059)
Oil
3.0 (.I 18)
Service sizemm (in.)
0.25 LO1 0),0.50 (.020),0.75 (.030), 1 .oo l.039)Oversize
Piston ring
Side clearancemm (in.)
No. 1
No. 2
End gap
mm (in.)
No. 1
No. 2
Oil ring side railmm (in.)
Service sizemm (in.)
0.03 - 0.07 (.0012 - .0028)
0.02 - 0.06 l.0008 - .0024)
0.30 - 0.45 (.0118 - .0177)
0.45 - 0.60 (.0177 - .0236)
0.20 - 0.60 (.0079 - .0236)
0.25 (.OlO), 0.50 (.020),0.75 (.030), 1 .oo (.039)Oversize
0.1 (.004)
0.1 (.004)
0.8 i.031)
0.8 l.031)
1 .o (.039)
Connecting rod
Bendmm (in.)
Twist
mm (in.)
Big end to thrust clearancemm (in.)
Piston pin press-in load
N (Ibs.)
0.05 i.0020) or less
0.1 (0.004) or less
0.10 - 0.25 (.0039 - .0098)
7,500 - 17,500 (1,686 - 3,934)
0.4 l.016)
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II-IOENGINE - Troubleshooting
TROUBLESHOOTINGmiwm
SymptomProbable cause
RemedyI,aJ
Compression too low) Cylinder head gasket blown1 Replace gasketI
Piston ring worn or damage
Piston or cylinder worn
Replace rings
Repair or replace piston and/or cylinder
block
Valve seat worn or damage
Repair or replace valve and/or seat ring
3il pressure drop
Engine oil level too lowCheck engine oil level
Oil pressure switch faulty
Oil filter clogged
Replace oil pressure switch
Install new filter
Oil pump gears or cover worn
Thin or diluted engine oilReplace gears and/or cover
Change engine oil to correct viscosity
1 Oil relief valve stuck (opened)) Repair relief valve
Excessive bearing clearance
Replace bearingsIbOil relief valve stuck (closed)
Incorrect lash adjusterRepair relief valve
Replace lash adjuster Oil pressure too high
Noisy valves
Thin or diluted engine oil (low oil pressure)Change engine oil
Valve stem or valve guide worn or damageReplace valve and/or guide
Connecting rod noise/
nain bearing noiseInsufficient oil supplyCheck engine oil level
Thin or diluted engine oilChange engine oil
Excessive bearing clearanceReplace bearings
Timing belt noise
Incorrect belt tensionAdjust belt tension
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II-12ENGINE - Service Adjustment Procedures-
r
AdJl
bolt
Alternator wllev
haft
Fixing nutOlFOOO8
Alternator pulley
Adjusting bolt
/Crankshaftpulley
Air contionercompressorpulleyw Tension pulleyFlxtng nutOlN007.
Crankshaft pulleyOlN007TENSION ADJUSTMENT OF THE ALTERNATOR DRIVE
BELT
I(1) Remove front under cover panel ’
aero> (Refer to GROUP 51 - Aero Parts.).\\
3 ’
(2) Remove under covers (front L.H., side L.H.).
(3) Loosen tension pulley fixing nut.
(4) Adjust belt deflection with adjusting bolt.
(5) Tighten fixing bolt.
(6) Run the engine one time or more.
(7) Check the belt tension. Readjust, if necessary.
(8) Install under covers.
DEFLECTION ADJUSTMENT OF THE ALTERNATOR AND
AIR CONDITIONER COMPRESSOR DRIVE BELT with air conditioner>
(1) Use straight handle box wrench to loosen tension pulley
fixing nut.
(2) Adjust belt deflection with adjusting bolt.
(3) Use straight handle box wrench to tighten fixing nut.
(4) Run the engine one time or more.
(5) Check the belt deflection. Readjust, if necessary.
DEFLECTION ADJUSTMENT OF POWER STEERING PUMP
DRIVE BELT(1) Insert an extension bar (insertion depth 12.7 mm), etc. into
the opening at the end of the tension pulley bracket.
(2) Loosen the tension pulley fixing bolts in the order of B and
(3)
iove the extension bar installed to the tension pulley in the‘LJdirection of arrow to adjust the belt tension.
(4) Tighten the tension pulley fixing bolts in the order of A and
8.Tightening torque: 35
- 50 Nm (25 - 36 ftlbs,)(5) Give the crankshaft two turns in normal direction (clock-
wise) to run in the belt.
(6) Check the belt deflection. Readjust, if necessary.
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ENGINE - Service Adiustment ProceduresII-13
I_ ianltion tlminaI!H Connector for Igdpstment 6rown)
4tll II -7FUO9371IGNITION TIMING ADJUSTMENTMllFLAF
(1) The vehicle should be prepared as follows before the
inspection and adjustment.
lEngine coolant temperature: 80 - 95°C (176 - 205°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: neutral
(P for A/T)l Steering wheel: neutral position
(2) Insert a paper clip to the connector, and connect a
tachometer to the paper clip.
NOTEDo not use the Multi-use tester.
If tested with the Multi-use tester connected to the
diagnosis connector, the ignition timing will not be the basic
timing but be ordinary timing.
(3) Set the timing light.
(4) Start the engine and run at idle.
(5) Check curb idle speed.
Curb idle speed: 700
f 100 rpm
NOTEThe engine speed indicated is a third of actual speed. In
other words, the reading of the tachometer times 3 is actual
speed.
(6) Turn OFF the ignition switch.
(7) Using a jumper wire, ground the ignition timing adjusting
terminal.
NOTEGrounding this terminal sets the engine to the basic ignition
timing.
\(8) Start the engine and run at idle.
(9) Check basic ignition timing.
Basic ignition timing: 5” BTDC
k 2”
(10)lf not within the standard value range, loosen the crank
angle sensor mounting nut and adjust by turning the crank
angle sensor. Turning it to the counterclockwise retards
timing, and to the clockwise advances it.
(1 l)After adjustment, tighten mounting nut taking care not to
move the crank angle sensor.
(12)Turn OFF the ignition switch.
(13)Disconnect the jumper wire connected at step (7).
(14)Start and run the engine at curb idle speed.
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ENGINE - Enaine AssemblvII-19
Engine mount bracketSERVICE POINTS OF REMOVALMllSBEH
15. DISCONNECTION OF Ail? CONDITIONER COMPRES-SOR
/ 16. POWER STEERING OIL PUMP
Disconnect air conditioner compressor and power steering
oil pump (with the hose).
NOTEThe removed air conditioner compressor and power steer-
ing oil pump should be fastened (by using rope, etc.) in
.aposition that will not interfere with the removal/installation
of the engine assembly.
34. REMOVAL OF ENGINE MOUNT BRACKETBefore removing the engine mount bracket installation bolt,
use a chain block or similar arrangement to suspend the
engine assembly (to the extent that there is no looseness of
the chain).
37. REMOVAL OF ENGINE ASSEMBLYAfter checking that the cables, hoses, harness connectors,
etc. are all removed, slowly raise the chain block to lift the
engine assembly upward out of the engine compartment.
SERVICE POINTS OF INSTALLATIONMl
1SDBC
37. INSTALLATION OF ENGINE ASSEMBLYWhen mounting the engine, check to be sure that the
cables, hoses, harness connectors, etc. are all in the correct
position.
34. INSTALLATION OF ENGINE MOUNT BRACKETAttach the engine mounting bracket so that the arrow mark
on the mounting stopper is in the direction as shown in the
illustration.
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11-24ENGINE - Cylinder Head Gasket
ldentlfrcatlonmark
01 N009iOlL0472
0111044
JI
j:: 1: :: ::p:i
c1
Q80401Q5 c
Frontbank074930296
- OlL105j8
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5SERVICE POINTS OF REMOVALMllJBBF
6. REMOVAL OF INTAKE CAMSHAFT SPROCKET
(1) Using a wrench, hold the camshaft at its hexagon and
remove the camshaft sprocket bolt.
Caution
Locking the camshaft sprocket with a tool damages
the sprocket.(2) Remove the camshaft sprockets.
14. REMOVAL CYLINDER HEAD ASSEMBLYUsing the special tool, remove the cylinder head assembly.
SERVICE POINTS OF INSTALLATION
MllJDEJ
15. INSTALLATION OF CYLINDER HEAD GASKET
(1) Make sure that the gasket has the proper identification
mark for the engine.
(2) Lay the cylinder head gasket on the cylinder block with
the identification mark at the front top.
14. INSTALLATION OF CYLINDER HEAD ASSEMBLY
(1)Use a scraper to clean the gasket surface of the cylinder
head assembly.
CautionTake care that no foreign material gets into the
cylinder, coolant passages or oil passages.
(2) Using the special tool and a torque wrench, tighten the
bolts to the specified torque in the order shown in the
illustration. (in two or three cycles)
CautionInstall the head bolt washers with shear droop
upward as shown in the illustration.
(3) Back off the bolts once and tighten them to the
specified torque as shown in step (2).

ENGINE - Cylinder Head Gasket11-25
Rear bank
6 011 010 09
Front bank
6
OlL105C6. INSTALLATION OF INTAKE CAMSHAFT SPROCKET
Using a wrench, hold the camshaft at its hexagon and
tighten the bolt to specification.
Caution
Locking the camshaft sprocket with a tool damages the
sprocket.5. INSTALLATION OF ROCKER COVER
Tighten the rocker cover bolts in the order shown in the
illustration.
NOTE(1) Only No. 5 bolt in the rear bank differs from other bolts
in length.
Rear bank No. 5 bolt._.._.._........._._____.__.._.. 20 mm (.79 in.)
Except rear bank No. 5 bolt
.._._............... 10 mm (.39 in.)
(2) Bolts are color-coded for the front and rear banks as
follows:
Front bank
__.._................_.......................................... Black
Rear bank . . . . . . . . . . ..___..................................._._._.............Green(3) When the rocker cover gasket has been replaced,
tighten bolts in this order, and then retighten bolts 1 to 6
to 4 Nm (2.9 ft.lbs.).
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11-28ENGINE - Timing Belt
Tlmlng mark01 N009E
A : :y,y;i;,$yi *&:;.~:;>
Exhaust valveside
*
/’*
120"* -1"
(*
6
7.^^^J‘c;Y
1zv w**
Intake valveside
Front bank
* : Approx. 35” o1 N0, og
Rockercoverslde
Exhaust valveside
Front bank
t~mng markOlNOlO
12. INSTALLATION OF TIMING BELT
(1) Align the timing marks on the respective sprockets.
In case of the camshaft sprockets in the front bank,
I~
proceed as follows:@ Install the crankshaft pulley. Shift the timing mark
on the crankshaft sprocket by three teeth to lower
the piston in No. 1 cylinder slightly from the top
dead center on compression stroke.
CautionTurning the camshaft sprocket with the piston
in No. 1 cylinder located at TDC on compression
stroke may cause the valves to interfere with the
piston.@ Make sure that the timing marks on the camshaft
sprockets for intake and exhaust valves are not
within the range A in the illustration at left.
If the timing mark is within range A, turn the
camshaft sprocket to move the timing mark to the
area closest to the range A.
CautionIn range A, the cam lobe on the camshaft lifts
the valve through the rocker arm and the
camshaft sprocket is apt to rotate by reaction
force of the valve spring. Therefore, be careful
not to have the finger pinched between the
sprockets.@ Turn the camshaft sprocket for either the intake or
exhaust valve to locate the timing mark as shown in
\the illustration at left. Then turn the other crankshaft
to locate the timing mark-as shown in the illustration
at left.
CautionIf the intake and exhaust valves of the same
cylinder lift simultaneously, interference with
each other may result. Therefore, turn the intake
valve camshaft sprocket and the exhaust valve
camshaft alternately.@ Turn the camshaft sprocket clockwise to align the
timing marks.
If the camshaft sprocket has been turned excessive-
ly, turn it counterclockwise to align the timing
marks.
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.@ Align the timing mark of the crankshaft sprocket.
NOTEShift the timing mark of the crankshaft sprocket one
teeth in counterclockwise direction to facilitate belt
installation.

ENGINE - Timing Belt11-29
OlN004t
& Pin hole
nilnq
8(2) Using paper clips, install the timing belt in the following
order with care not to allow the belt to slack.@ Exhaust camshaft sprocket (front bank side)
+ @
Intake camshaft sprocket (front bank side)
-+ @Waterpump pulley
+ @ Intake camshaft sprocket (rear bank
side)
+ @ Exhaust camshaft sprocket + @ Idler pulley
-+ @ Crankshaft sprocket + @ Tensioner pulley
NOTESince the camshaft sprockets turn easily, secure them
with box wrenches to install the timing belt.
Caution1. Be careful, the camshaft is turned by the reac-
tion of valve spring.
2.If the timing belt is reused, install it so that thearrow marks made at removal are in the direc-
tion of rotation.
(3) Turn the tensioner pulley so that its pin holes are
located above the center bolt. Then, press the tensioner
pulley against the timing belt and, at the same time,
temporarily tighten the center bolt.
(4) Check that the timing marks on all sprockets are aligned
properly.
(5) Remove the four clips.
. ADJUSTMENT OF TIMING BELT TENSION
(1) Rotate the crankshaft
114 turn counterclockwise, then
rotate it clockwise until the timing marks are aligned.
(2) Loosen the center bolt on the tensioner pulley. Using
the special tool and torque wrench, apply tensioning
torque to the timing belt and, at the same time, tighten
the center bolt to specification.
Specified torque:
10 Nm (7 ftlbs.)
[Timing belt tensioning torque]
Caution
When tightening the center bolt, make sure that thetensioner pulley is not rotated together.
(3) Remove the set pin from the auto tensioner. At this
time, make sure that the set pin can be easily removed.
(4) Rotate the crankshaft two turns clockwise and leave it
as is for five minutes or more. Then, check again that
the set pin can be easily removed from, and installed to,
the auto tensioner.
NOTEEven if the set pin cannot be easily inserted, the auto
tensioner is normal if its rod protrusion is within
specification.
Standard value (A): 3.8
- 4.5 mm (.I49 - .I77 in.)
If the protrusion is out of specification, repeat steps (1)
to (4).
(5) Check again that timing marks on all sprockets are
aligned properly.
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