1991 MITSUBISHI 3000GT service

11-36ENGINE - Cylinder Head and Valve
SquarenssVALVE SPRINGS
(1) Check free length of each valve spring and replace if
necessary.
!
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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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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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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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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11-46ENGINE - Piston and Connecting Rod
7EN246 1
7EN247
MD998765
(Pus:rod)
7EN25;
lENOl17
BEARINGMeasure the inner diameter of the connecting rod bearing and
the outer diameter of the crankshaft pin. If the oil clearance
exceeds the limit, replace the bearing, and crankshaft if
necessary.
Standard value: 0.016
- 0.046 mm (.OOOS - .0018 in.)
Limit: 0.1 mm
(.004 in.)
NOTEFor the method by which the oil clearance is measured using a
plastigauge, refer to the item on the crankshaft.
SERVICE POINTS OF INSTALLATION
MllTDAQ9. INSTALLATION OF PISTON PIN
(1) Insert the special tool, Pushrod into the piston pin and
install the guide A.
(2) Apply engine oil to the outside of the piston pin.
(3) Assemble the piston and connecting rod lining up the
front marks.
(4) Insert the guide A end of the piston pin assembled in
step
(1) into the piston through the pin hole on the front
mark.(5) 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.
(6) Using a press, install the piston pin.
If the installation load is smaller than the standard value
range, replace the piston pin (piston assembly) and/or
the connecting rod.
Standard value: 7,500 - 17,500 N (1,686 - 3,934 Ibs.)TSB Revision

ENGINE - Crankshaft. Flvwheel and Drive Plate11-51
id
PLASTIGAGE METHODMllUlAA
Plastigage may be used to measure the clearance.
(1) Remove oil and grease and any other dirt from bearings and
journals.(2) Cut plastigage to the same length as the width of the
bearing and place it in parallel with the journal, off oil holes.
(3) Install the crankshaft, bearings and caps and tighten them
to the specified torques. During this operation, do NOT turn
the crankshaft. Remove the caps. Measure the width-of the
plastigage at the widest part by using a scale printed on the
plastigage sleeve.
If the clearance exceeds the repair limit, the bearing should
be replaced.
Should the standard clearance not be obtained even after
bearing replacement, replace the crankshaft.
SERVICE POINTS OF INSTALLATIONMllUDAM
16. INSTALLATION OF CRANKSHAFT BEARING (UPPER) /
15.10. THRUST BEARING A / 14.11. THRUST BEARING
B
/ 12. CRANKSHAFT BEARING (LOWER)
(1) Classify the crankshaft bearings (upper and lower) by
whether there is an oil groove or not. Then, assemble asshown in the illustration.
(2) Assemble the thrust bearings (A and
B) on the No.3
journal area as shown in the illustration.
CautionInstall them with the groove side facing outward.Crankshaft bearing (upper)
Oil groove
Thrust bearing A
Front of engine(Tlmlng belt side)
EN269
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ENGINE - Engine Oil Cooler
ENGINE OIL COOLER
REMOVAL AND INSTALLATION
11-55
MllMA-.4Nm
2.9 ft.lbs.40-45
Nrh
29 - 33 ft.lbs.Removal steps
1.Front splash shield extensionl *2. Engine oil feed hose3.Engine oil return hose
4*4. Engine oil return tube5. Engine oil cooler
12Nm
9 ft.lbs.5
02FOOOi
SERVICE POINTS OF REMOVALMllMBAC
2.REMOVAL OF ENGINE .OIL FEED HOSE / 4. ENGINE OIL
RETURN TUBE
CautionBe sure to hold the weld nut of the oil cooler while
loosening the eye bolt.
INSPECTIONMllMCAC
l
Check the engine oil cooler fins for bends, breaks or plugs.l Check the engine oil cooler hoses for cracks, damage,
clogging or deterioration.l Check the gaskets for damage or deformation.
l Check the eye bolts for clogging or deformation.
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