| 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 |
| CYLINDER HEAD BOLT CAUTION |
Cylinder Head Bolt Caution On
Isuzu 2.6L Engines
A loose head bolt has been found to be the cause of coolant leaks on some Isuzu 2.6L engines. The leakage occurs at the center head bolt on the exhaust manifold side of the engine and seems to be caused by high engine temperatures. This heat may cause the head bolt to stretch and lose its clamping ability, allowing coolant to seep past the head gasket and into the combustion chamber. If the loosened bolt is not replaced, there is a possibility th at coolant deposits will accumulate on the exhaust valve's seating ace.
Correction of this situation requires removal of the cylinder head and complete inspection of the exhaust valves for deposits. Install a new head gasket and replace all head bolts. See the illustration below and torque bolts in sequence to 58-72 ft. lbs. All components must be torqued to specification prior to
adjusting the valve train. The engine may be rotated by the using a 17 mm wrench/socket on the power steering pulley nut. Cold valve adjustment specification for both intake and exhaust is .008.
The AERA Technical Committee |
| CRANKSHAFT CAUTION FOR 3.2L ISUZU ENGINES |
Crankshaft Caution For
1996-2002 Isuzu 3.2L Engines
The AERA Technical Committee offers the following crankshaft caution for 1996-2002 Isuzu 3.2L engines. This caution is expressed to engine rebuilders when crankshaft replacement is required. This engine series has used two different crankshaft assemblies during the above mentioned time period. Intermixing those crankshafts may produce a no-start situation.
The difference in the crankshafts is in the diameter of the ignition reluctor wheel attached to between the 3rd and 4th rod journal. The measurement difference is only slight and may not be noticed if only visual comparison of the two crankshafts is made.
To determine which crankshaft you?re working on it is suggested to measure outside diameter of the reluctor wheel on the crankshaft and refer to the chart below.
Application Engine Model Reluctor Diameter OE Crank Part #
1996-97 ? 6VD1 6.937 (176.200 MM) 8971094432
1997 ? -2002 6VD1W 7.250 (184.150 MM) 8791318572
The difference, however, is enough to interrupt the ignition signal from the crankshaft to allow a no start condition. Changing the crankshaft out to is one method of correction and removing the old reluctor wheel and placing it on the replacement crankshaft is another.
The AERA Technical Committee |
| HYDRAULIC LIFTER REPLACEMENT ON 3.2L SOHC ENG. |
Hydraulic Lifter Replacement On
1992-96 Isuzu 3.2L SOHC Engines
The AERA Technical Committee offers the following information regarding hydraulic lifter replacement on 1992-96 Isuzu 3.2L SOHC engines. This information applies to new, rebuilt or lifters that have been disassembled and cleaned.
To assure proper operation of this lifter, it should be primed with engine oil before it is installed into the rocker arm. Doing so will eliminate the possibility of the lifter being dislodged before the lifter is fully primed with pressurized engine oil.
To prime this lifter submerge it in clean engine oil, then gently compress and decompress the lifter until no air bubbles come out while doing so. The rocker arm should then be dipped in oil and the lifter inserted into the rocker arm. Assemble all lifter/rockers and then reassemble those components to their rocker shaft. This procedure will also prevent trapped air in the rocker arm socket, even though the lifter is self-bleeding.
The AERA Technical Committee |
| REAR CRANKSHAFT OIL SEAL LEAK |
Rear Crankshaft Oil Seal Leak On
1992-1994 4BD2TC GM Diesel Engines
The AERA Technical Committee offers the following information for rear crankshaft oil seal leaks on 1992-94 4BD2TC GM diesel engines*. This four cylinder turbocharged diesel engine is used in GMC and Chevrolet W4 model trucks. If this leaking condition can be verified as coming from the rear main seal, installing a revised oil seal may resolve the leak.
The installed position of this seal, Part #97072823, is critical to assure an effective seal. When correctly installed, the seal depth should be .445-.468 (11.3-11.98 mm) below the rear face or the crankshaft. The use of tool number J41269 (Figure 2) is also advised to minimize seal distortion during installation.
Trucks that are equiped with an automatic transmission require the removal of the pilot bushing before installing a new seal. After installing the new seal, install the flywheel/flexplate and torque the mounting bolts to 115 ft. lbs.
* This engine is built for GM by Isuzu Motors.
The AERA Technical Committee |
| PISTON PROTRUSION |
Piston Protrusion On
1985-97 Isuzu 4BD1/T & 4BD2-TC Diesel Engines
The AERA Technical Committee offers the following information on piston protrusion for 1985-97 Isuzu 4BD1/T & 4BD2-TC diesel engines. The following information has not been previously published in Isuzu service manuals. The information listed below has been obtained from engines during disassembly and verified by Isuzu engine builders.
Engine Desired Piston Protrusion
4BD1 .020-.034 (.508-.864 mm)
4BD1-T .020-.034 (.508-.864 mm)
4BD2-TC .020-.037 (.508-.940 mm)
These engines have been observed to suffer from cylinder block/head deck erosion that is observed during disassembly, most often because of a head gasket failure. If erosion is noted, the head and block surfaces require resurfacing before they can be placed back in service.
Engines assembled with piston protrusion higher than the listed specifications may produce excessive cylinder pressure or allow piston to valve contact. Excessive cylinder pressure may lead to engine or head gasket failure.
AERA members are adjusting the center to center distance of this engine?s connecting rod. In some instances, the standard size factory bushing Part #ES1-12251-027 can be used. In other situations where a more dramatic correction is required, a bushing that has a .020 smaller inside diameter is used.
AERA is currently aware of one aftermarkert supplier for the .020 smaller ID bushing with Part #S4653L. One AERA member has also reported occasional connecting rod bolt breakage if the bolts are not replaced during engine assembly.
The AERA Technical Committee |
| CAM TIMING CHAIN MARK |
Cam Timing Chain Marks On
1976-88 Isuzu 1.8 & 1.9L Engines
AERA members have expressed some confusion aligning cam timing marks on 1976-88 Isuzu 1.8 & 1.9L engines. The confusion starts while reading service manual information referencing marked plates on the cam timing chain. Apparently, some aftermarket timing chains do not have the marked plates which indicate the correct positioning for installation. The original equipment chain has two marked plates that must align with sprocket marks when properly installed.
The installation of an unmarked timing chain can be achieved by ensuring the correct number of links are between the cam and crankshaft sprocket marks. To correctly position the sprocket marks also depends on which direction you are counting, clockwise or counter clockwise.
When properly timed, the number of plates between the sprocket marks will be 24 counting in a clockwise direction. The number of plates counting counter clockwise should be 21, when the chain is properly installed. Both timing methods are viewed from the front of the engine.
The AERA Technical Committee |
| CRANKSHAFT SPECIFICATIONS |
Crankshaft Specifications On
1985-89 Isuzu 2.0L VIN F Engines
The AERA Technical Committee offers the following crankshaft specifications for 1985-89 Isuzu 2.0L VIN F engines. It appears that depending upon the
source, different crankshaft journal diameters have been published. The amount of difference is slight, but could cause an engine failure if the incorrect
specifications are used to grind the crankshaft.
The correct diameter for the connecting rod journal is 1.9262-1.9268 (48.925-48.940 mm). The correct diameter for the main bearing journal is 2.2016-
2.2022 (55.921-55.936 mm).
Crankshaft Specifications Oil Clearance
Connecting Rod Journal 1.9262-1.9268 .0007-.0020
(48.925-48.940 mm)
Main Bearing Journal 2.2016-2.2022 .0008-.0020
(57.980-58.00 mm)
Stroke 3.2283 (82.00 mm)
End Play .002-.010 (.051-.254 mm)
Previously published information indicated the main journal diameter could be as much as .0016 larger than the above specifications. Whereas, the rod
journal may have been as much as .0014 (.0356 mm) larger. If an engine is assembled with either of these situations, there may be insufficient bearing
oil clearance.
The AERA Technical Committee |
