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

                                Oil Starvation Of The Cylinder Head On
                                        1986-89 Acura 1.6L Engines

AERA machine shop personnel are reminded to thoroughly clean the vertical oil passage in the cylinder block when rebuilding 1986-89 Acura 1.6L engines.  This engine also uses an oil control jet at the block deck in that vertical oil gallery.  It too must be removed, cleaned and free of obstructions.  Note that the opening of the control valve is only .040 (1.02 mm) in diameter (see illustration).

Anytime the cylinder head is removed from the engine, the oil control jet needs to be removed from the gallery.  Once removed the vertical gallery should be flushed from the lower oil supply gallery.  Pressurized air will work if the engine has been disassembled.  If the engine has not been removed from the vehicle, oil can be forced through the gallery by turning the engine with the starter.  Be sure to install a new gasket under the control jet before positioning the cylinder head gasket and mounting the head.

Failure to reinstall the oil control valve will force too much oil into the cylinder head.  This may render the valve seals ineffective or overwhelm the PCV system, causing excessive oil consumption.  
 
                                                                             The AERA Technical Committee

                                              Snapping Noise On
                                       1990-91 Acura 1.8L Engines

The AERA Technical Committee has been advised of a snapping noise on
1990-91 Acura 1.8L engines.  The best description for this noise is a sharp snapping sound, similar to the sound of spark plug wire arcing.  The cause for this unusual noise is not obvious, but may be uneven cylinder head torque.

Inappropriate torque may permit the cylinder head to move as the engine reaches operating temperature.  If this noise is detected and o other cause can be found, verify the cylinder head bolt torque with this procedure: 

      1.   Allow the engine to completely cool and remove both camshafts.
      2.   In reverse sequence loosen cylinder head mounting bolts, one bolt at a 
            time, then torque each bolt immediately to 7 ft. lbs.
      3.   After all bolts have been tightened to 7 ft. lbs. in sequence, tighten all 
            bolts to 22 ft. lbs. Finally, advance the head bolt torque to 43 ft. lbs,
            then 61 ft. lbs.
      4.   Reinstall the camshafts and adjust valve clearance to .006 for intake   
            valves and .007 for exhaust valves.

                                                                             The AERA Technical Committee

                                              Engine Ticking Noise On
                                      1999-2003 Acura 3.2 & 3.5L Engines

The AERA Technical Committee offers the following information regarding an engine ticking noise on 1999-2003 Acura 3.2& 3.5L engines. This noise occurs after the cylinder head has been removed for machining and reinstalled on the engine. The information contained in this bulletin applies to engines reassembled with original equipment head gaskets.

Inadvertently the incorrect cylinder head gaskets may have been installed on this engine. Some cylinder head gaskets were mispackaged with the incorrect cylinder bore diameter in the gasket. Instead of getting the correct 3.5040" (89 mm) bore gasket, gaskets with a 3.3858 (86 mm) bore were packaged for this engine. 

The ticking noise that is heard is actually the pistons hitting the head gaskets as they approach top dead center (TDC). If the cylinder head gasket, as shown in Figure 1 below has a P8C stamped on it, the incorrect gasket was installed. The correct gasket should have the letters PGE stamped on it, Part #1255-PGE-A01.
 
Acura Part Numbers
Front Gasket Set Kit Part #06110-PGK-A11
Rear Gasket Set Kit Part #06120-PGK-A11

                                                                        The AERA Technical Committee

                                                 Oil Consumption On
                                      1986-94 Acura 1.6, 1.7 & 1.8L Engines

The AERA Technical Committee offers information on oil consumption on 1986-94 Acura 1.6, 1.7 & 1.8L engines. Acura considers oil consumption when the rate is in excess of one quart to one thousand miles traveled. This engine uses a 
metered oil supply to the cylinder head by means of a removeable metal oil jet located in the deck of the cylinder block.

The oil jet meters a certain amount of engine oil to the cylinder head components. During the removal process of the cylinder head, it may stick to the head and be misplaced during cleaning and handling. If the oil jet, Part 
#15140PM3000, is not reinstalled during assembly, excessive amounts of engine oil will enter the cylinder head. This additional amount of oil will then collect under the valve cover and overwhelm the valve stem seals. The oil may also 
enter the PCV system if the level becomes high enough. In either case, oil will enter the combustion process or the exhaust system causing oil loss.

Some AERA members increase the opening size of this orifice slightly, anytime the cylinder head has been removed from the block. Drilling the existing restrictor to .062 (1.575 mm) in size will increase the volume of oil to the cylinder 
head and camshaft. That procedure has been beneficial during cold starts when ambient temperatures are very low.

Increasing the orifice hole size slightly should not overwhelm the cylinder head with oil, providing all other oil clearances are within specifications. 

                                                                                The AERA Technical Committee

                                      New Cylinder Liner O-Ring Seals On
                                      Cummins NH/NT 6 Cylinder Engines

Cummins Engine Company has released new O-ring seals for the cylinder liners in NH/NT 6 cylinder engines.  The new seals are made of an EP material and have a smaller diameter cross-section.

The new seal replaces both the old center seal #3008998 and the old lower seal #183049.  The new seal carries Cummins part #3032874 and is black in color with one blue dot.

The new O-ring seals are not to be intermixed with the former seals on the same liner.  Cylinder liner deformation will result.  You can use the former seals and new seals in the same engine as long as they are used in the correct combinations on each liner.  The illustration below shows the correct combinations.

                                                                       The AERA Technical Committee

                                               Oil in Cooling System on
                                         VW 1.5L & 1.6L Diesel Engines

AERA members have reported instances of engine oil in the cooling system on VW 1.5L diesel engines.  According to AERA sources, the problem is related to a crack in the cylinder head bolt hole located near the oil gallery feeding the cylinder head.

The oil feed gallery in the block is located on one side of the center head bolt hole and a coolant jacket is on the opposite side of the bolt hole.  Pressurized engine oil is diverted through a slot in the head gasket and is feed up the side of the head bolt to the cylinder head.  The oil also follows the bolt back down to the bottom of the bolt hole.  Should the crack in the head bolt hole extend to the coolant jacket, oil can mix with engine coolant.

This problem is generally found on engines equipped with 11mm head bolt holes.  Later design engines utilize 12mm head bolts and do not exhibit this defect.  At the time of this writing no successful repair procedure is available.

                                                                       The AERA Technical Committee