| The following technical bulletins were published by AERA. |
| | CYLINDER HEAD BOLT TORQUE FOR 4 & 6 G MITSUBISHI ENGINES | Cylinder Head Bolt Tightening Caution For
1992-1996 Mitsubishi 4G & 6G Series Engines
The AERA Technical Committee offers the following information regarding cylinder head bolt tightening caution on 1992-1996 Mitsubishi 4G & 6G series engines. Information previously published in the OEM service manuals was incorrect and the following specifications should be used.
Installing non-elastic head bolts use the following torque values for vehicles/engine.
For torque sequence see Figure 1 to tighten in three steps use the bolt tightening sequence, if applicable. Refer to sequence chart. Note: Designations such as Turbo, Non-Turbo, SOHC and DOHC are only used if these items cause variations to the torque information of the engine.
Years Models Engine Torque
1992-95 Mirage thru May 1995 4G1 / 1.5L 53 ft/lbs (73 Nm)
1992-94 Eclipse 4G3 / 1.8L 53 ft/lbs (73 Nm)
1992 Eclipse, Galant 4G6 / 2.0L 80 ft/lbs (108 Nm) DOHC
1992 Galant, Expo & Truck 4G6 / 2.4L 80 ft/lbs (108 Nm) SOHC
1995 Galant 4G6 / 2.5L 80 ft/lbs (108 Nm) SOHC
1992-95 Truck, Montero, Galant 6G7 / 3.0L 80 ft/lbs (108 Nm) SOHC
& Diamante
1993-95 Diamante Wagon 6G7 / 3.0L 80 ft/lbs (108 Nm) SOHC
1992-95 Diamante & 3000 GT 6G7 / 3.5L 80 ft/lbs (108 N m) DOHC non-Turbo
1992-95 3000 GT 6G7 / 3.0L 91 ft/lbs (123 N m) DOHC Turbo *
* Loosen all bolts and retighten to 91 ft/lbs.
1994-95 Montero 6G7 / 3.5L 80 ft/lbs (108 N m) DOHC Turbo
Figure 1. Cylinder Head bolt torque Sequence
Installing Elastic Head Bolts (plastic-angle tightening method).
Before reusing head bolts measure the shank lengths of ALL the head bearing bolts, if measurement of (see below) exceeded or the bolt has visual damage REPLACE THE BOLTS. Measure from the tip to the shoulder under the bolt head (not to the shoulder of the washer). See Figure 2
1995-96 Mirage after 5/95 4G9 / 1.5L ** 4.063" (103.200 MM) SOHC 16Valve
1993-96 Mirage 4G9 / 1.8L *** 3.795" (96.400 MM) SOHC 8Valve
1992-95 Expo LRV 4G9 / 1.8L 3.795" (96.400 MM) SOHC 8Valve
1993-96 Eclipse 4G6 / 2.0L 3.913" (99.400 MM) S & D 16 Valve 1993 Galant 4G6 / 2.0L 3.913" (99.400 MM) S & D 16 Valve
1993-95 Expo, Expo LRV & Truck 4G6 / 2.4L 4.740" (120.400 MM) SOHC 8 Valve
1994-96 Galant 4G6 / 2.4L 4.740" (120.400 MM) SOHC 8 Valve
Figure 2. Cylinder Head Bolt Shank Measurement
For torque sequence see Figure 3 to tighten elastic head bolts using the plastic/angle tightening method; the following procedure is applicable to all the engines listed below.
Step 1; Torque all bolts (in sequence) to specification 58 ft/lbs (78 Nm). ***
Step 2, Loosen all bolts fully.
Step 3, Tighten all bolts to 14 ft/lbs (20 Nm).
Step 4, Tighten using a breaker bar (not a torque wrench) 90° rotation.
Step 5, Repeat step four.
Note: ** For the 1995-96 Mirage after 5/95 initial torque is a lower value Step one Torque all bolts (in sequence) to specification 34 ft/lbs (49 Nm).
*** For the 1993-96 Mirage & 1992-95 Expo LRV initial torque is a lower value Step one Torque all bolts (in sequence) to specification 54 ft/lbs (74 Nm).
Figure 2. Cylinder Head Bolt Shank Measurement
Figure 3. Cylinder Head Bolt Torque Sequence.
The AERA Technical Committee | | CYLINDER HEAD BOLT TORQUE SPECIFICATIONS | Cylinder Head Bolt Torque Specifications On
Mitsubishi Engines
The AERA Technical Committee is announcing revised cylinder head torque values for various Mitsubishi engines. Previously there may have been some confusion since torques were listed in both hot or cold specifications.
Consider the cold torque specifications listed below when mounting cylinder heads on various Mitsubishi engines. Do not retorque the cylinder head bolts when the engine is hot.
53 lbs.ft. 80 lbs.ft. 87 lbs.ft.
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1.5L Mirage 1.6L 1985-92 2.3L Diesel 1983-85
1985-92 1.8L 1983-88
1.8L* Eclipse 2.0L 1983-92
1990-92 2.4L 1985-92
2.6L 1983-92
3.0L** 1988-2000
* 1992 1.8L Expo LRV = 14.5 lbs.ft., + 1/4 turn + 1/4 turn.
** 1991-92 3.0L 3000GT = 90 lbs.ft. loosen all bolts, retorque all bolts to 90 lbs.ft.
The AERA Technical Committee | | MAIN BEARING BOLT TORQUE CAUTION ON MITSUBISHI 4/6 G ENGINES | Main Bolt Tightening Caution For
1992-1999 Mitsubishi 4G & 6G Series Engines
The AERA Technical Committee offers the following information for main bolt tightening caution on 1992-1995 Mitsubishi 4G & 6G series engines. Information previously published in the OEM service manuals was incorrect and the following specifications should be used. The information in TB 2039 has abeen updated and it should be destroyed, as it is no longer valid information.
To install non-elastic main bearing bolts, the following procedure is applicable to all vehicles/engine listed below.
Tighten the bolts on each main bearing cap equally until the specified torque is achieved. Use the bolt-tightening sequence shown in Figure 1 if applicable.
Years Models Engine Torque
1992-95 Mirage 4G1/1.5L 38 ft/lbs (53 Nm)
1992-94 Eclipse 4G3/1.8L 38 ft/lbs (53 Nm)
1992 Galant, Expo & Truck 4G6/2.0&2.4L 38 ft/lbs (53 Nm) SOHC
1992 Eclipse, Galant 4G6/2.0L 49 ft/lbs (68 Nm) DOHC
1992-95 Truck,Montero,Galant,
Diamante 6G7/3.0L 57 ft/lbs (79 Nm) SOHC
1993-95 Diamante Wagon 6G7/3.0L 57 ft/lbs (79 Nm) SOHC
1992-95 Diamante & 3000 GT 6G7/3.0L 67 ft/lbs (93 Nm) DOHC Non/Turbo
1992 3000 GT 6G7/3.0L 67 ft/lbs (93 Nm) DOHC Turbo
1993-95 3000 GT 6G7/3.0L 54 ft/lbs (74 Nm) DOHC Turbo
1994-95 Montero 6G7/3.5L 54 ft/lbs (74 Nm) DOHC Turbo
Elastic main bolt tightening (plastic-angle tightening method). Before reusing main bolts measure the shank lengths of ALL the main bearing bolts. If the measurement of 2.799 (71.100 MM) is exceeded or the bolt has visual damage REPLACE THE BOLTS. Measure from the tip to the shoulder under the bolt head (not to the shoulder of the washer) see figure 3.
To tighten elastic main bearing bolts using the plastic/angle tightening method; the following procedure is applicable to all the engines listed below.
1. Torque bolts (in sequence see figure 2) to specification 18 ft/lbs.
2. Using a breaker bar (not a torque wrench), tighten each bolt 90°.
3. Using a breaker bar (not a torque wrench), turn each bolt an additional 90°.
The following vehicles/engines use elastic main bearing bolts:
1993-95 Mirage 4G9/1.8L 18 ft/lbs (25 Nm) Plus 90°, +90°
1992-95 Expo LRV 4G9/1.8L 18 ft/lbs (25 Nm) Plus 90°, +90°
1993-95 Eclipse 4G6/2.0L 18 ft/lbs (25 Nm) Plus 90°, +90°
1993 Galant 4G6/2.0L 18 ft/lbs (25 Nm) Plus 90°, +90°
1993-95 Expo, Expo LRV,
Truck 4G6/2.4L 18 ft/lbs (25 Nm) Plus 90°, +90°
1994-95 Galant 4G6/2.4L 18 ft/lbs (25 Nm) Plus 90°, +90°
The AERA Technical Committee | | CONNECTING ROD NUT TORQUE CAUTION | Connecting Rod Nut Tightening Caution On
1992-1995 Mitsubishi 4G Series & 6G7 Engines
The AERA Technical Committee offers the following information for connecting rod nut tightening caution on 1992-1995 Mitsubishi 4G Series & 6G7 engines. Information previously published in service manuals was incorrect and the following specifications should be used.
Years Models Engine Torque
1992-95 Mirage 4G1 14 FT/LBS (20 Nm) plus 90°
1992-94 Eclipse 4G3 25 FT/LBS (34 Nm)
1992 Eclipse, Galant, Mirage 4G6 38 FT/LBS (52 Nm)
Expo & Truck
1993-95 Eclipse, Galant, Mirage 4G6 14 FT/LBS (20 Nm) plus 90°
Expo LRV and Truck
1993-95 Mirage 4G9 14 FT/LBS (20 Nm) plus 90°
1992-95 Expo LRV
1992-96 Truck, Diamante (wagon) 6G72 38 FT/LBS
3000 GT, Montero & Galant
1992-95 Truck, Diamante (wagon) 6G74 25 FT/LBS (34 Nm) plus 90°
3000 GT, Montero & Galant
Note: If the above listed specifications are not used, engine failure may occur.
The AERA Technical Committee | | ENGINE NOISE ON 1983-92 ENGINES | Engine Noise On Mitsubishi
1983-92 1.6, 1.8, 2.0, 2.4L Engines
AERA members have reported engine noise on 1983-92 Mitsubishi four cylinder engines. This noise is most noticeable at cold engine start-up and is loudest in the timing cover area. It has been described as a high pitched whine and may be coming from the engine's oil pump.
To help reduce this type of noise, a revised oil pump is now available. This new pump uses a helical gear set, compared to the previous spur type gears (see illustration below). To purchase an improved design oil pump, a new case assembly and two individual gears must be ordered. Those components are also different for the various engines and cannot be intermixed with each other or the previous design.
Part Number Part Description Usage Vehicle
MD170852 Front Case Assembly 2.0L SOHC 1989-92 Galant
2.4L SOHC 1992 Expo
MD170854 Front Case Assembly 1.8L SOHC 1983-88 Cordia &
Tredia
2.0L SOHC 1984-88 Cordia &
Tredia
2.4L SOHC 1985-92 Galant,
Pickup & Van/Wagon
MD175762 Front Case Assembly 2.0L DOHC 1989-92 Galant
2.0L DOHC 1990-92 Eclipse
MD179151 Front Case Assembly 1.6L DOHC 1989-92 Mirage
MD174580 Oil Pump Drive Gear 1.8L SOHC 1983-88 Cordia &
Tredia
2.0L SOHC 1984-88 Cordia &
Tredia
2.4L SOHC 1985-92 Galant,
Pickup & Van/Wagon
MD174581 Oil Pump Drive Gear 1.6L DOHC 1989-92 Mirage
2.0L SOHC 1989-92 Galant
2.0L DOHC 1989-92 Galant,
Eclipse
2.4L SOHC 1992 Expo
MD174582 Oil Pump Driven Gear Used in all applications
listed above.
All engines built from engine build code LX8939 and up have been assembled with the new oil pump components.
The AERA Technical Committee | | EXCESSIVE OIL CONSUMPTION | Excessive Oil Consumption
on 1978-89 Chrysler Jet Valve Engines
AERA members have reported excessive oil consumption and spark plug fouling complaints on 1978-89 Chrysler jet valve engines. These engines are manufactured for Chrysler Corporation by Mitsubishi Motor Corporation of Japan.
There are several possibilities for allowing oil to pass into the combustion chamber. They are oil leaking past the valve stem seal or the jet valve body O-ring, or a worn jet valve body or valve stem. Since oil can travel among the various air passages in the cylinder head casting, it is important to inspect all jet valves not just the cylinder that is indicated by a fouled spark plug.
Remove the jet valve assembly as indicated in the appropriate service manual and inspect the O-ring for nicks, cuts, tears or deformation. Likewise, a brittle O-ring is not capable of sealing out lubricating oil. The O-ring, Chrysler part #MD009786, should be replaced whenever the jet valve assembly is removed from the cylinder head.
Disassemble the jet valve assembly and inspect the valve stem seal for damage or deformation. Chrysler recommends replacement of the complete assembly if the valve body or valve stem are worn. Use Chrysler part #MD009440.
Any oil residue or carbon must be removed from the jet valve passages before assembly. See the appropriate OE or aftermarket manual for further information and torque values.
The AERA Technical Committee |
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