| The following technical bulletins were published by AERA. |
| | INTERFERENCE ENGINES | Interference Engines
The AERA Technical Committee would like to offer the following information on engines that present the possibility of interference between pistons and valves. The interference or contact may bend valve(s) when the timing between the camshaft and crankshaft is interrupted. This is generally the result of a timing belt or chain breaking or slipping.
The following list are engines that AERA is currently aware of that have exhibited interference. There may be other engines that are not listed below that have the possibility of piston to valve contact. If the engine you are working on is not listed, do not assume that it is a freewheeling design. It is suggested to add to this listing as additional information is obtained.
ACURA
1986-89 1.6L Integra
1991-95 1.7L Integra
1990-95 1.8L Integra
1986-89 2.5L Legend
1992-94 2.5L Vigor
1986-89 2.7L Legend
1990 2.7L Legend
1991-95 3.0L NSX
1991-95 3.2L Legend
AUDI
1970-93 All Except 1970-77
1.9L & 1970-73 1.8L
BMW
1987-95 2.5L 325I 525I
1994-95 4.0L 740I
CHRYSLER
1993-95 1.5L Colt
1987-88 1.5L Colt
1992-95 1.5L Eagle Summit
1987-88 1.6L Colt
1989-92 1.6L Eagle Summit
1994-98 2.0L Neon Stratus
1990-95 2.0L Eagle Talon
DAIHATSU
1988-92 1.0L Charade
1988-92 1.3L Charade
1990-92 1.6L Rocky
FIAT
1974-79 1.3L 128 Series
1979-82 1.5L Stranda
1974-78 1.6L 124 Series
1974-78 1.8L 124 Series
1974-78 1.8L 131 Series, Brava
1979-82 2.0L Brava, Spider
FORD
1981-85 1.6L Escort, EXP
1981-83 1.6L LN7, Lynx
1984-85 2.0L Escort, Tempo
1993-95 2.0L Probe
1986-88 2.0L Ranger
1984-87 2.0L Lynx, Topaz Diesel
1985 2.2L Ranger
1989-92 2.2L Probe
1986-88 2.3L Ranger
1986-87 2.3L Diesel Ranger
1991-98 4.6L Crown Victoria
GM
1986-95 1.0L Geo Metro
1989-91 1.0L Firefly (CANADA)
1985-88 1.5L Sunburst (CANADA)
1985-89 1.5L Spectrum
1990-93 1.6L Prizm, Storm
1981-84 1.8L Diesel (CANADA)
1982-86 1.8L Buick Skyhawk
1990-98 1.9L Saturn
1987-88 2.0L Buick Skyhawk
1988-95 2.3L Quad Four
1985-87 3.0L Buick
1979-95 3.8L Buick
HONDA
1986-87 1.0L Prelude
1973-78 1.2L All
1973-78 1.3L All
1980-84 1.3L All
1973-78 1.5L All
1985-89 1.5L Civic
1988-95 1.5L Civic, CRX
1993-95 1.5L Civic Del Sol
1979-84 1.5L All
1985-87 1.5L CRX
1993-95 1.6L Civic Del Sol
1973-78 1.6L All
1980-82 1.6L All
1988-95 1.6L Civic, CRX
1984-87 1.8L Prelude, Accord
1979-83 1.8L All
1986-91 2.0L Prelude
1990-91 2.1L Prelude
1990-95 2.2L Prelude, Accord
1992-95 2.2L Prelude
1995 2.7L Accord
HYUNDAI
1984-95 1.5L Excel Scoupe
1995-98 1.5L Accent
1992-95 1.6L Elantra
1993-95 1.8L Elantra
1992-95 2.0L Sonata
1989-91 2.4L Sonata
1990-95 3.0L Sonata
INFINITI
1990-92 3.0L M30
ISUZU
1987-89 1.5L I-Mark
1990-93 1.6L Stylus Impulse
1987-89 2.0L Impulse
1981-87 2.2L Diesel Truck
1986-95 2.3L Truck Trooper
1988-95 2.6L Truck Rodeo Amigo
1991-96 3.2L Trooper Rodeo Amigo
KIA
1995 2.0L Sportage
MAZDA
1984-85 2.0L 626
1988-92 2.2L 626 MX6
1989-93 2.2L Pickup
1988-95 3.0L 929 MPV
MITSUBISHI
1985-95 1.5L Mirage Precise
1990-92 1.6L Mirage
1989-95 2.0L Galant Eclipse
1983-86 2.3L Diesel Pickup
1994-95 2.4L Galant
NISSAN
1982 1.5L Centra
1983-88 1.6L Sentra Pulsar
1987-89 1.8L Pulsar
1982-89 2.0L Stanza 300ZX
1984-95 3.0L Maxima 300ZX Pathfinder
PORSCHE
1976-83 2.0L 924
1976-89 2.5L 944 Series
1989 2.7L 944 Series
1989-91 3.0L 944 Series
1976-83 4.5L 928
1984 4.7L 928
1985-91 5.0L 928
1992-95 5.4L 928
SUZUKI
1985-94 1.3L Samurai Sidekick
1989-94 1.3L Swift
TOYOTA
1986-95 1.5L Tercel
1981-83 2.2L Pickup
1984-87 2.4L Pickup
1982-88 2.8L Celica Cressida
1987-94 3.0L 4-Runner
VOLKSWAGEN
1976-91 All Except 1.9 2.1L Engine
1990-92 1.6L Golf (CANADA) Jetta
1990-95 2.0L GTI Jetta GLI Passat
VOLVO
1991 2.3L Coupe 940
1986-94 2.3L 240 740 940
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 | | VALVE STEM SEAL IDENTIFCATION ON MITSUBISHI 3.0L ENGINES | Valve Stem Seal Identification On
2000-02 Mitsubishi 3.0L VIN H Engines
AERA members have reported a difficulty correctly identifying valve stem seals on 2000-02 Mitsubishi VIN H engines. To properly identify the two different valve stem seals, Mitsubishi has color-coded the seals.
Upon removing the valve seals from the packaging, there may not be any identification sheet with the seals. This leaves the machinist wondering which seal goes on the intake valve and which one on the exhaust valve. To correctly install these seals, the one with charcoal gray identification color goes on the exhaust and the one with the green identification color goes on the intake.
Color Location Part #
Charcoal Gray Exhaust MD184303
Green Intake MD307342
AERA is currently unaware of an aftermarket supplier of the valve stem seals mentioned above.
The AERA Technical Committee | | LOOSE OIL PUMP PICKUP SCREENS | Loose Oil Pump Pickup Screen On
GM 2.8L (173 CID) Engines
Reuse of the oil pump pickup screen on GM 2.8L (173 CID) engines may result in low engine oil pressure and related problems.
The OE oil pump for this engine is manufactured out of aluminum whereas most aftermarket oil pumps are manufactured out of traditional cast iron. Removing the oil pump pickup screen, cleaning it and then reinstalling it in an aftermarket oil pump may result in a loose fit.
Apparently, the diameter of the opening that accepts the pickup screen in the aluminum pump is smaller than in the cast iron counterpart. This tight fit shrinks the diameter of the pickup screen, but is necessary because of the differing expansion rates between the aluminum oil pump housing and the steel pickup
screen. Reusing the same screen in a cast iron pump that does not require this much interference fit, and therefore features a slightly larger bore, may result in an undesirable loose fit of the screen. This could draw air into the lubricating oil system causing low oil pressure, valve train noise and lead to serious
engine damage.
The AERA Technical Committee recommends the replacement of all oil pump pickup screens as part of the remanufacturing process on light duty engines.
For additional information see AERA Bulletins: TB 680, TB 439 & SB 140
The AERA Technical Committee | | CYLINDER HEAD CRACKS | Cylinder Head Cracks On
1983-86 GM 2.0L (121 CID) Engines
AERA member machine shops have reported cracking of the cylinder
heads of 1983-86 GM 2.0L (121 CID) engines. Complaints of coolant in the engine oil may be a futher indication.
This engine joined the GM lineup in 1983 and featured a cast iron cylinder head assembly through the 1986 model year. The engine has been used in the J cars as well as S-10 pickup trucks. As of the 1987 model year the cylinder head is now manufactured out of aluminum.
Cracks have been noticed in the cast iron cylinder head near the valve spring seats at the top of the casting. Usually cracks develop across the #6 intake valve spring seat and continue across and behind the #4 and #5 exhaust valve spring seat. Magnetic particle inspection should be used to determine the
extent of the crack and what repairs, if any, may be performed.
A neglected cooling system may deteriorate the casting where a small amount of stress will induce cracks. Cracks may also be caused by engine freeze up, overheating, or disassembly of the engine without adequate cool down.
The AERA Technical Committee | | BURNED JET VALVES | Burned Jet Valves On
Chrysler (Mitsubishi) 2.6L Engines
The AERA Technical Committee offers the following consideration for Chrysler 2.6L engines with repeated jet valve burning problems. This problem is most prevalent with engines that utilize hydraulic lash compensators (HLC). Reported failures have usually been shortly after cylinder head installation or
compensators replacement.
Unless the jet valves are readjusted after the engine has reached operating temperature, improper clearances will result. The correct lash adjustment of .010 (.254mm) can only be achieved of the HLC plunger is in its operating location. If the jet valve is adjusted before that point, or on the bench, operating oil pressure will change the previous clearance. Insufficient clearance may hold the jet valve off the seat and eventually burn it.
The AERA Technical Committee | | REVISED CRANK ON 92-96 2.0L ENGINES | Revised Crankshaft On
1992-96 Mitsubishi 2.0L Engines
AREA members have reported a revised crankshaft on 1992-96 Mitsubishi 2.0L engines. The area of revision is the thrust width and flywheel flange. At first glance, the crankshaft would appear to be the same as previous crankshafts.
Modification to the thrust area of the crankshaft involved reducing the length by approximately .130 (3.302 mm). The number of flywheel mounting bolt holes was also increased from six, to seven. It also appears, that the length of all other main bearing journals has been reduced slightly.
Years Used Thrust Length Number Of Rear Bolt Holes
1983-91 1.144 (29.58 mm) 6
1992-96 1.013 (25.53 mm) 7
Currently, main bearings sets are only available from Mitsubishi.
The AERA Technical Committee |
|
|
