1991 MITSUBISHI 3000GT lock

11-24ENGINE - Cylinder Head Gasket
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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
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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
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Exhaust valveside
*
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120"* -1"
(*
6
7.^^^J‘c;Y
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Intake valveside
Front bank
* : Approx. 35” o1 N0, og
Rockercoverslde
Exhaust valveside
Front bank
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12. INSTALLATION OF TIMING BELT
(1) Align the timing marks on the respective sprockets.
In case of the camshaft sprockets in the front bank,
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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
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& Pin hole
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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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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
125 Nm90 ftlbs.
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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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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ENGINE - Cylinder Head and Valve
Oversize I.D.
Valve(2) Rebore the valve seat hole in
oversize valve seat diameter.Seat Insert Oversizescylinderhead to a selected
DescriptionSize mm (in.)1 Size mark /Seat insEt(,ke;ght H/Cylinder head I.D.
mm (in.)
Intake valve0.3i.012)0,s.
I
30
I
7.5-7.7(.295-,303)36.300-36.325(1.4291-1.4301)
seat insert
0.6(.024)O.S.607.8-8.0(.307-,315)36.600-36.625(1.4409-1.4419)
Exhaust valve
seat insert
0.3l.012)0,s.7.9-8.1(.311-.319)33.300-33.325(1.3110-1.3120)
0.6(.024)O.S.8.2-8.4t.323-,331)33.600-33.625(1.3228-1.3238)
7EN02E(3) When press-fitting the valve seat, chill the valve seat with
liquid nitrogen so that the cylinder head bore is not
damaged by galling.
(4)Using the valve seat grinder or cutter, correct the valve seat
to the specified width and angle.
(5) See “VALVE SEAT RECONDITIONING PROCEDURES.”
VALVE GUIDE REPLACEMENT PROCEDURE
MllPJDB
(1) Using suitable rod and a press, press the valve guide out of
the cylinder head toward the cylinder block side.
(2) Rebore the valve guide hole to the oversize valve guide
outside diameter
to be press-fitted.
CautionDo not use a valve guide of the same size as the one
removed.12.250-12.268
(.4823-.4830)12.500-12.518
(.4921-.4928)(3) Install the valve guide until a protrusion of 17.5 mm
(.689in.) is obtained. See the illustration.
NOTE1. Press-fit the valve guide from the cylinder head top
surface.
2. Note the difference in lengths of the valve guides for
the intake and exhaust: intake 45.5 mm (1.791 in.) and
exhaust 50.5 mm (1.988 in.).
3. After the valve guide has been installed in position,
insert a new valve to ensure that it slides smoothly.
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11-38ENGINE - Cylinder Head and Valve
Enamelcoatedside
Springretainer
Stem seal
pring sheet
6EN024SERVICE POINTS OF INSTALLATION
MllODAH15.13. INSTALLATION OF VALVE STEM SEAL
Install the spring seat, then using the special tool, install the
stem seal by lightly tapping the tool.
d
Caution1. Incorrect installation of the seal without using the
special tool will result in poor sealing and cause oilleakage down valve guide.
2. Do not reuse stem seal.
11.7. INSTALLATION OF VALVE SPRING
Valve springs should be installed with the enamel coated
side toward the valve spring retainer.
9. 5. INSTALLATION OF RETAINER LOCK
Using the special tool, install the retainer lock
4. INSTALLATION OF CYLINDER. HEAD GASKET
Identification mark:

2DN
2DT
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