engine MITSUBISHI 3000GT 1991 Repair Manual

11-36ENGINE - Cylinder Head and Valve
SquarenssVALVE SPRINGS
(1) Check free length of each valve spring and replace if
necessary.
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FreelengthStandard value: 46.9 mm
(1.846 in.)\bJLimit: 45.9 mm
(1.807 in.)
(2) Using a square, test squareness of each valve spring. If
spring is excessively out of square, replace it.
Standard value: Less than 2”
Limit: 4
1 EN035
VALVE GUIDES
1 EN29ECheck the valve stem-to-guide clearance. If the clearance
exceeds the service limit, replace the valve guide with new
oversize part.
Standard value:
Intake
Exhaust0.02 - 0.05 mm (0008 - .0020 in.)
Limit:0.05
- 0.09 mm (.0020 - .0035 in.)
Intake
Exhaust0.10 mm (0039 in.)
0.12 mm (0047
in.)6EN043
1AVALVE SEAT RECONDITIONING PROCEDURES
(I 1 Before valve seat reconditioning, check valve stem to guide
clearance.
(2)Recondition the valve seat with a seat grinder or cutter. The
valve seat width should be the specified value at the center
of the valve face.
Inspect the valve seat with prussian blue to determine
LJwhere the valve contacts the seat. To do this, coat valve
seat lightly with prussian blue, and then set valve in place.
Rotate the valve with light pressure. If the blue is
transferred to the center of valve face, contact is satisfac-
tory.
If the blue is transferred to top edge of the valve face, lower
valve seat with a 30 degrees stone or cutter. If the blue is
transferred to the bottom edge of valve face, raise valve
seat with a 65 degrees stone or cutter.
Valve seat diameter:
Intake34 mm (I .34 in.)
ExhaustSeat width: 0.9
29.5 mm (1.16 in.)
- 1.3 mm (035 - .051 in.)
(3) The valve and valve seat should be lapped with a lapping
compound.
VALVE SEAT REPLACEMENT PROCEDURE
(1) Grind the valve seat to be replaced from the inside to thin
the wall thickness. Then, remove the valve seat.
1 ENOE18
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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.
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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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L
,
LENGINE
- Cylinder Head and Valve11-391. INSTALLATION OF CYLINDER HEAD BOLT
(1) Using the special tool, tighten the bolts in two to three
stages in the illustrated sequence.
(2) Back off the bolts once and tighten them to the
specified torque as shown in step (1).
7EN0262
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II-40ENGINE - Oil Pan and Oil Pump
OIL PAN AND OIL PUMPREMOVAL AND INSTALLATIONMllRA--
d
,,,/jgfq/Y “ 10 Nm14
75 Nm55 ftlbs.
I
19 Nm14 ft.lbs.
45 Nm33 ft.lbs.
51u00105LUOOll
Sealant: 3M ATD Part No. 8660 or
equivalent6Nrn
5 tklbs.
7EN0317
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Groove 4Groove 4Bolt hole 0110156Bolt hole 0110156portionportionportionportion
sealant: MITSUBISHI GENUINE PartNo. MD9971 10 or equivalen
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ENGINE - Oil Pan and Oil Pump
Removal steps
1. Transaxle stay (front)
2. Transaxle stay (rear)
3. Oil pressure switch4.
Z:
;:9.10.l+11.l*12.** l * 13.
Oil pressure gauge unitOil filterOil cooler by-pass valve
Oil filter bracket stay
Oil filter bracket
Oil filter bracket gasket
Drain plugDrain plug gasket0; y; boltI
16. Relief plug17. Relief spring18. Relief plunger** 19. Crankshaft front oil seal
20. Oil pump case
21. Oil pump gasket
22. Oil pump cover
23. Oil pump outer rotor
24. Oil pump inner rotor
14. Oil screen
15. Oil screen gasket
Side
clearance
BodyclearanceSERVICE POINTS OF REMOVALMllRBBB
13. REMOVAL OF OIL PAN
(1) Knock the special tool in deeply between the oil pan and
cylinder block.
(2) Hitting the side of the special tool, slide and remove the
oil pan.
INSPECTION
OIL PUMPMllRKAB
Assemble the rotor on the oil pump and check the clearance
with a feeler gauge.
Standard value:
Body clearanceO.lOO- 0.181 mm (.0039 - .0071 in.)
Side clearance0.040 - 0.095 mm (.0016 - .0037 in.)
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II-42ENGINE - Oil Pan and Oil Pump
6LUOl;
Oil pumpcase7EN0139
Sealant coating area(Top view)
4 mm (. 16 in.) diameterOIL COOLER BY-PASS VALVE
(1) Make sure that the valve moves smoothly.
(2) Ensure that the dimension L measures the standard value
under normal temperature and humidity.
Dimension L: 34.5 mm (1.358 in.)
(3) The dimension must be the standard value when measured
after the valve has been dipped in 100°C (212°F) oil.
Dimension L: 40 mm (1.57 in.) or more
SERVICE POINTS OF INSTALLATIONMllRDEC
19. INSTALLATION OF CRANKSHAFT FRONT OIL SEALUsing the special tool, knock the oil seal into the oil pump
case.
NOTEKnock it as far as the surface.
13. APPLICATION OF SEALANT TO OIL PAN
(1) Apply specified sealant all around the oil pan flange to a
diameter of 4 mm
(.I6 in.).
Specified sealant: MITSUBISHI Genuine Part No.
MD9971 10 or equivalent(2) Install the oil pan within 15 mins. after applying the
liquid gasket.
Dead sealant
Groove areaBolt hole area7EN0305
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iENGINE
- Oil Pan and Oil Pump11-43
Tlghtenlng sequence of flange bolts(bottom view)
iTiming beltside)7EN030f
7EN030
12. TIGHTENING SEQUENCE OF OIL PAN BOLTTighten the flange bolts in the sequence shown in the
illustration.illustration.
11. INSTALLATION OF DRAIN PLUG GASKETInstall the drain plug gasket in the direction shown in the
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11-44ENGINE - Piston and Connecting Rod
PISTON AND CONNECTING RODREMOVAL AND INSTALLATIONMllTA--
r
Removal steps
1. Nutl * I)*2. Connecting rod cap
l *3. Connecting rod bearing (lower)
4. Piston, connecting rod assembly
1_ ._5. $nnec$ng. rod bearing (upper)WV WC 6. rrston ring No. 1l * **7. Piston ring No. 2
I)+ 8. Qil ringl * ._ - -’v* Y. Hston oin10. Piston11. Connecting rod
12. Bolt52
ihn38 fklbs.
7EN0266
6EN18!SERVICE POINTS OF REMOVAL
MllT6EC2. REMOVAL OF CONNECTING ROD CAP
Mark the large end of the connecting rod with the cylinder
number for use during reassembly.
6. REMOVAL OF PISTON RING No. 1
/ 7. PISTION RING
No. 2
Remove the piston rings with a piston ring expander.
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ENGINE - Piston and. Connectina RodII-45
LJ
Front mark
-
MD998764
lEN0113
lEN0114
v5EN057
,, Push in by thepiston.
IPiston ringPistonring gap6EN0379. REMOVAL OF PISTON PIN
(1) Insert the special tool,
Pushrod from the front mark side
of the piston top and install the guide B.
(2) With the piston top facing the front mark side of the
special tool, Piston Pin Setting Base and the piston front
mark facing up, set the piston and connecting rod
assembly.
(3) Using a press, remove the piston pin.
NOTEAfter the piston pin is removed, store the piston, piston
pin and connecting rod as grouped for each cylinder
number.
INSPECTION
PISTON RING
MllTCEA
(1) Check the clearance between the piston ring and the ring
groove. When it exceeds the limit, replace the rings, the
piston, or both.
Standard value:
No.10.03 - 0.07 mm (.0012 - .0028 in.)
No.20.02
- 0.06 mm (.OOOS - ‘0024 in.)
Limit: No.10.1 mm (.004 in.)
No.20.1 mm
(.004 in.)(2) Insert the piston ring into the cylinder bore putting it against
the top of the piston head and pressing it in.
When it makes a right angle, measure the piston ring gap
with a feeler gauge. When the gap is too large, replace the
piston ring.
Standard value:
No.10.30-0.45 mm (.0118- .0177 in.)
No.20.45- 0.60 mm (.0177 - .0236 in.)
Oil ring side rail0.20 - 0.60 mmLimit: No.1
(.0079 - .0236 in.)
0.8 mm
(.031 in.)
No.20.8 mm
(.031 in.)
Oil ring side rail1 .O mm (.039 in.)
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LJ
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