engine MITSUBISHI 3000GT 1991 Workshop Manual
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1991, Model line: 3000GT, Model: MITSUBISHI 3000GT 1991Pages: 1146, PDF Size: 76.68 MB
Page 76 of 1146

11-26ENGINE - Timing Belt
TIMING BELT
REMOVAL AND INSTALLATION
MllKA-BI
Pre-removal Operationl Removal of the Under Cover (Front L.H.,side L.H.)l Removal of Front Under Cover Panel
l Raise and Suspend the Engine to the ExtentForce is not Applied to the Engine Mounti LIOO-
120 Nm72 - 87 ft.lbs.
35 Nm25 ft.l$.
TurbochargerOSFOO03
lo-12Nm7 - 9 ft.lbs.
Removal steps
1. Air hose
11 31 ftlbs.
‘5IO-12Nm
B;p 49ftJbs.
\
180- 190 Nm130 - 137 ft.lbs.
2. Air pipe
3. Tensioner assembly
4. Drive belt (power steering)
(RefertoP.ll-11.)4** I)* 5. Crankshaft pulley’6. Brake fluid level sensor
7. Timing belt upper cover
8. Engine mount bracket
9. Idler pulley (alternator
/ air conditioner)+* l * 10. Engine support bracketl * 11. Timing belt lower coverl * lAdjustment of timing belt tensionl * l a 12. Timing beltl * 13. Auto tensionerNm
[email protected].
Post-installation Operation
l Installation of Alternator Assembly(Refer to GROUP 16 -Alternator.)
l Installation of the Under Cover(Front L.H., Side L.H.)l Installation of Front Under Cover Panel
l Installation of Cruise Control Actuator
M D998754nSERVICE POINTS OF REMOVAL
5. REMOVAL OF CRANKSHAFT PULLEYMllKBEF
,Using special tools, remove the crankshaft pulley from the
crankshaft.
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CautionUse only the specified special tools, or a damaged
pulley damper could result.
,
LJ
Page 77 of 1146

ENGINE - Timinn Belt11-27
r bol
I01 NO07
10. REMOVAL OF ENGINE SUPPORT BRACKETRemove the engine support bracket in the numbered
sequence shown in the illustration.
Spraying lubricant, slowly remove the bolt (reamer bolt)
indicated by the arrow.
CautionKeep in mind that the reamer bolt is sometimes heat
seized on the engine support bracket.
Timing mark
mshaftrocket01 N009:
d Soft jawSoft jaw
OlL104E
Set hole
n
12. REMOVAL OF TIMING BELT(1) Align the timing marks.
(2) Make a mark on the back of the timing belt indicating
the direction of rotation so it may be reassembled in the
same direction if it is to be reused.
(3) Loosen the center bolt on the tensioner pulley to
remove the timing belt.
Caution
Water or oil on the belt shorten its life drastically, sothe removed timing belt, sprocket, and tensioner
must be free from oil and water. These parts should
not be washed. Replace parts if seriously contamin-
ated.
If there is oil or water on each part check. the front
case oil seals, camshaft oil seal and water pump for
leaks.SERVICE POINTS OF INSTALLATION
MllKDDB
13. INSTALLATION OF AUTO TENSIONER
(‘I) If the auto tensioner rod is in its fully extended position,
reset it as follows.@ Keep the auto tensioner level
and: in that position,
clamp it in the vise with soft jaws.@ Push in the rod little by little with the vise until the
set hole @ in the rod is aligned with that @ in the
cylinder.
CautionPush in the rod slowly to prevent the push rod
from being damaged.@ Insert a wire [I
.4 mm (.055 in.) in diameter] into the
set
ho&.@ Unclamp the auto tensioner from the vise.
(2) Install the auto tensioner.
CautionLeave the wire installed in the auto tensioner.
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Page 78 of 1146

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.
Page 79 of 1146

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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Page 80 of 1146

II-30ENGINE - Timing Belt
hread diameter x length
mm (In.)
6x201.23 x ,781fllllO4F
1 Thread diameter x Lengthmm (in.)
2(39
x1.06)l.47 x 2.50)OlN0072
11. INSTALLATION OF TIMING BELT FRONT COVER (LOW-
ER)Since the mounting bolts of timing cover are different in
size depending on location, insert them with care.
.\J
10. INSTALLATION OF ENGINE SUPPORT BRACKETSince the mounting bolts of engine support bracket are
different in size depending on location, insert them in
numbered sequence.
CautionWhen installing the reamer bolt, tighten it, slowly
spraying lubricant on the reamer area.
\/,,fjd99p54-II5. INSTALLATION OF CRANKSHAFT PULLEY
Using the special tool, attach the crankshaft pulley to the
crankshaft.
CautionUse only the specified special tools, otherwise a
:damaged pulley damper could result.
d
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Page 81 of 1146

ENGINE - Rocker Arm and Camshaft11-31
ROCKER ARM AND CAMSHAFTREMOVAL AND INSTALLATION
11 Nm8 ftlbs.
MllZA-0
7EN0244
Removal steps
I. Crank angle sensor adaptor2. Bearing cap front3.Oil seal
4. Bearing cap rear
5.Circular packing6.Bearing cap No.27.Bearing cap No.4
8.Bearing cap No.3
9.Camshaft10.Rocker arm11.Lash adjuster
Installation steps
11. Lash adjuster10. Rocker arml * 9. Camshaft*a 8. Bearing cap No. 3l *7. Bearing cap No. 4l *6. Bearing cap No. 2** 4. Bearing cap rearI)* 2. Bearing cap front*+ 5. Circular packingl 43. Oil sealI. Crank angle sensor adaptor
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Page 82 of 1146

11-32ENGINE - Rocker Arm and Camshaft
r
I
/7EN024E
Small wire
8ENOO58
Identification mark(stamped on hexagon section)
7EN0249
Front sideINSPECTION
MllZCAB
CAMSHAFTMeasure cam height (longer diameter of the cam). If it exceeds
the limit, replace the camshaft.
Standard value:
Intake side
35.49 mm (1.3972 in.)
Exhaust side
35.20 mm (1.3858 in.)
Limit:
Intake side
34.99 mm (1.3776 in.)
Exhaust side
34.70 mm (1.3661 in.)SERVICE POINTS OF INSTALLATION
MllZDAK
11. INSTALLATION OF LASH ADJUSTER
(1) Immerse the lash adjuster in clean diesel fuel.
(2) Using a small wire, move the plunger up and down 4 or
5 times while pushing down lightly in the check ball in
order to bleed out the air.
(3) Install the lash adjuster to the cylinder head.
9. INSTALLATION OF CAMSHAFT
(1) Turn the crankshaft to bring No.1 cylinder to the top
dead center.
(2) Check that the rocker arm is installed correctly on the
lash adjuster and valve.
(3) Install the camshaft noting the identification mark
(stamped on the hexagon sectioned).
Identification mark: Intake sideV
Exhaust side C
(4) Install the camshafts with their dowel pins positioned
as shown in the illustration.
Rear side ,
Approx. 100”
Pl
Frontm&k
M
0
/
Cap No
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Identificationmark
7EN03168. 7. 6. 4. 2. INSTALLATION OF BEARING CAPS
(1) Install noting the identification mark and cap No. No.2, 3
and 4 bearing caps bear the front mark. Install these
caps with the mark lined up with the front mark on the
cylinder head.
Identification mark: Intake side
IExhaust side E
Page 83 of 1146

ENGINE - Rocker Arm and Camshaft11-33
About 10 mm C.39 In.17ENO248
i,(2) Tighten gradually in two or three steps and finally
tighten to specified torque.
(3) Measure the camshaft end play. Replace if the limit is
exceeded.
Standard value: 0.1
- 0.2 mm (.004 - .008 in.)
Limit: 0.4 mm
(.016 in.)
NOTEIf the bearing cap is installed with the cylinder cap
removed, the valve will protrude. Install, therefore, with
the cylinder head lifted by about
10 mm (.39 in.).
5. INSTALLATION OF CIRCULAR PACKING
Using the special tool, insert the circular packing.
3. INSTALLATION OF OIL SEAL
Using the special tool, insert the oil seal.
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Page 84 of 1146

II-34ENGINE - Cylinder Head and Valve
CYLINDER HEAD AND VALVEREMOVAL AND INSTALLATION
’ 104e------1510
11-A16-----P
Removal steps
l * l +I. Cylinder head bolt
2. Washer
3. Cylinder head assembly
l +4. Cylinder head gasket
** l *5. Retainer lock
6. Valve spring retainer
l *7. Valve spring
8. Intake valve
l * l *9. Retainer lock10. Valve spring retainer
7E NO254
l * 11. Valve spring12.Exhaust valvel 413.Valve stem seal
14. Valve spring sheet
I)* 15. Valve stem seal
16. Valve spring sheet
17. Intake valve guide
18. Exhaust valve guide
19. Intake valve sheet
20. Exhaust valve sheet
3
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Page 85 of 1146

ENGINE - Cvlinder Head and ValveII-35SERVICE POINTS OF REMOVAL
1. REMOVAL OF CYLINDER HEAD BOLT
Using the special tool, remove the cylinder head
u 1 \+-MD998735 15. 9. REMOVAL OF RETAINER LOCK
Using the special tool, remove the retainer lock.
’ 6EN02INSPECTION
CYLINDER HEAD
MllOBACbolts.
MllOCAO
(1) Using a straight edge and feeler gauge, measure the
flatness of the cylinder head gasket surface.
Standard value: 0.03 mm (0012 in.) or less
Limit: 0.2 mm
(008 in.)
(2) If the measured flatness exceeds the limit, grind and repair
the surface to gain the flatness of standard value or less.
Grinding Limit: 0.2 mm
(.008 in.)
Caution
When the cylinder block is assembled, 0.2 mm
(.008 in.)or less of grinding is permissible.
VALVESReplace the valve if the margin (thickness of the valve head)
exceeds the limit.
Standard value:
Intake side1.0 mm (039 in.)
Exhaust side1.5 mm (.059 in.)
Limit:
Intake side0.5 mm (019 in.)
Exhaust side1 .O mm (.039 in.)
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