| 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 |
| UPPER ENGINE OIL LEAKS |
Upper Engine Oil Leaks On
1989 Suzuki 1.3L DOHC (VIN 3) Engines
There have been instances of oil leaks on Suzuki 1.3L engines manufactured before February 10, 1989, caused by the front camshaft oil seal coming loose. Suzuki has found that this problem may be corrected by reducing the width of the seal. The original oil seal had a width of 8 mm and it has been replaced
with Part #09283-32026, which is 6 mm wide.
When installing the new seal, it is suggested that the front camshaft bearing cap be removed. The seal should be installed so that the outer seal surface is flush with the machined surface surrounding the seal bore. It is critical to ensure that the outer portion of the seal is not recessed in the seal housing bore (see illustration). Seal recession may restrict the oil return passage and cause premature oil seal failure. Re-torque the camshaft bearing cap bolts to 84-102 inch lbs. and the rocker cover bolts to 36-42 inch lbs.
Finally, inspect the timing belt for oil contamination. The belt should be replaced if there is any contamination or residue present. Operate the engine upon completion of this procedure and inspect for oil leaks.
The AERA Technical Committee |
| INTAKE MANIFOLD MODS IMPROVE COOLING |
Intake Manifold Modification Improves Cooling On
Suzuki 1.3L Engines
The AERA Technical Committee has recently become aware of a repair procedure on 1985-92 Suzuki 1.3L intake manifolds to improve engine cooling. Beginning in June 1992, a revised intake manifold went into production to supplement engine cooling. The change, effective VIN Code #JS4JC31C-N4102470 also involves a revised thermostat, which is not interchangeable with the older design.
It is possible to modify the older (1985-92) intake manifolds to take advantage of the revised thermostat and provide more effective engine cooling. The modification involves enlarging the water port opening to 1.890 and the thermostat mounting counterbore to 2.224. Refer to the illustrations below to
assist in the machining of the intake manifold.
The revised thermostat now incorporates a rubber O ring on the outside diameter to provide a more effective seal. There are currently two thermostats available, Part #17670-56B00 for 180 degree Fahrenheit opening, and Part #17670-56B10 for 190 degree opening.
The AERA Technical Committee |
| REVISED ENGINE SPECIFICATIONS |
Revised Engine Specifications On
1996-99 Suzuki 1.8L VIN 2 Engines
The AERA Technical Committee offers the following information on revised engine specifications for 1996-99 Suzuki 1.8L VIN 2 engines. Failure to use
these specifications may result in premature engine failure after assembly.
Apparently, Suzuki service manuals listed inaccurate information regarding connecting rod journal dimensions and torque values for the camshaft timing
sprocket bolts and the main bearing cap bolts. The dimension for the connecting rod journal is listed for a .010 (.25mm) undersize diameter. The correct specifications are listed below.
Engine Part Old Spec Revised Spec
.010 Undersize Rod Journal 1.9570-1.9591 1.9580-1.9586
Cam Timing Sprocket 43.5 ft/lbs 57.5 ft/lbs
Main Bearing Cap Bolt 18 ft/lbs 19.5 ft/lbs
The AERA Technical Committee |
| REVISED CYL. HEAD & ROCKER ARMS |
Revised Cylinder Head & Rocker Arms On
1992-96 Suzuki 1.6L SOHC Engines
AERA members have reported cylinder head and rocker arm modifications on 1992-96 Suzuki 1.6L SOHC engines. This design change occurred in June of 1992 and involved the spacing between the rocker arms. Intermixing of previous head, rocker arm and thrust springs should not be attempted. The changes affect the valve train geometry and could result in engine failure if the components are intermixed.
Cylinder heads may not be interchanged unless the rocker arms and spacer springs are also changed to the appropriate design. Currently both design heads are available from service parts under Part #111000-57B01 for the early head, and Part #111000-57B02 for the later.
Refer to the illustrations below to compare component differences.
The AERA Technical Committee |
| CON ROD CAUTION ON 1989-96 1.6L VIN O |
Connecting Rod Caution On
1989-96 Suzuki 1.6L VIN O Engines
The AERA Technical Committee offers the following information regarding a connecting rod caution on 1989-96 Suzuki 1.6L VIN O engines. It has been reported there are two styles of connecting rods used in these engines. One
uses a locked piston pin design and the other uses a full floating design. Using the incorrect rod for your application may lead to engine failure.
Apparently, engines were manufactured first for an interference fit between the connecting rod small end bore and their piston pin, thus locking the pin to the rod. That design evolved to a full floating design and the piston pin is maintained in the piston by clips.
The confusion started at the time the full floating assembly was introduced, as the rod did not incorporate a piston pin bushing. The pin is allowed to float within the small-end housing bore. It appears the manufacturing process only increased the small end diameter to create the desired clearances. All other aspects of the connecting rod remained similar.
Using a full floating rod on a locked style piston may cause an engine failure. Using a locked style rod on a full floating style piston may also cause an engine failure.
Some aftermarket piston suppliers are supplying only the full floating piston design. Some engine builders are using only that style piston and machining all 1.6L connecting rods to small end housing bore of .7481-.7485 (19.002-
19.012 mm). The desired piston pin to connecting rod small end housing bore oil clearance is .0001-.0005 (.0025-.0127 mm).
The AERA Technical Committee |
| CYL HEAD OIL RESTRICTOR |
Cylinder Head Oil Restrictor On
1989-95 GM 1.0L Engines
AERA members have reported some confusion on the cylinder head oil restrictor used on 1989-95 GM 1.0L engines. This engine uses hydraulic lash compensators in the cylinder head and the restrictor is used to control the amount of oil directed toward them. The confusion has been the correct location of the restrictor. Apparently some engines have it installed into the cylinder head and some in the cylinder block.
Regardless if the restrictor is screwed into the block or head, it also prevents excessive amounts of oil into the cylinder head area. If the oil control plug (restrictor) is not installed, the additional oil may overwhelm the PCV system and cause oil consumption.
When properly installed, this restrictor, Part #96051574, also acts as an anti-drainback valve and prevents lifter noise at start-up. This engine is made for GM by Suzuki and they also offer this restrictor under Part #11112-73001.
The AERA Technical Committee |
| TIMING CHAIN RATTL;ING NOISE ON 2.5L SUZUKI ENGINES |
Timing Chain Rattling Noise On
1999-2002 Suzuki 2.5L Engines
The AERA Technical Committee offers the following information regarding a timing chain rattling noise on 1999-2002 Suzuki 2.5L engines. This noise comes from the front of the engine behind the timing cover and is normally heard the loudest when the engine is cold. Vehicles that are affected are the Grand Vitara & XL-7.
There are 3 timing chain tensioners on this engine and causing this problem is the number 1 timing chain tensioner that is not properly adjusted. In order to fix this problem, Suzuki recommends replacement of the number 1 tensioner only as shown in the Figure 1 below. The new tensioner is being offered under Part #12831-85FA7. If there is a tensioner noise for the first 5 seconds of engine operation, Suzuki considers this normal under engine operation.
After installation of the tensioner, properly clean the sealing surface on the timing chain cover, crankcase, cylinder block and cylinder heads for installation. Apply sealant ?A" Suzuki Bond 1207F (Part #99000-31250) to the timing chain cover sealing surface as shown in Figure 2. Apply sealant ?B" Suzuki Bond 1207B (Part #99104-31140) to the mating surface of the cylinder block and head. Use a plastic scraper as a jig to force the sealer into the air gap formed between the cylinder block, head and head gasket as shown in Figure 2A.
NOTE: Failure to perform this step will result in an oil seepage that will migrate down the front of the block and be diagnosed as a crankshaft seal leak.
The AERA Technical Committee |
