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

                                                Flexplate Breakage On
                                           Ford 2.3L & 2.5L HSC Engines

AERA members have reported flexplate breakage on Ford 2.3L & 2.5L HSC engines used in the Ford and Mercury car line (Tempo, Topaz). Breakage usually occurs shortly after engine or crankshaft replacement.  The flexplate breaks in the center hub area where it contacts the crankshaft, eventually breaking out the entire section.  Prior to complete separation, a rattling or clicking noise may be heard at the rear of the engine.

This engine requires a metal reinforcement plate that is installed after mounting the flexplate to the crankshaft.  Omitting the reinforcement plate can cause undue localized stress on the flexplate bolt mounting area, eventually causing the flexplate to fracture and break.

To complete flexplate installation, apply sealer to the six 10 mm x 1.0 mm retaining bolts and torque to 54-64 ft. lbs.  The flexplate retaining bolt holes are open to the engines crankcase and may leak if sealer is not applied to the bolts.

                                                                        The AERA Technical Committee

                                Oversize Main Bearing Housings On Some
                                             Ford 2800 CC V6 Engines

Oversize main bearing housings have been found in some Ford 2800 cc V6 engines.  the subject engines had main bearing saddles in the block with .015 oversize housings.

Ford Motor Co. supplies .015 oversize OD bearings for this engine with Standard, .010, .020 and .030 undersize ID.

                                                                          The AERA Technical Committee

                                                Bearing Failures On
                                Ford 5.0 & 5.7L (302 & 351W CID) Engines

AERA members have experienced premature crankshaft bearing failures on 5.0 & 5.7L Ford engines.

Investigating these failures disclosed that all of the machined components were on size and the proper tolerances had been achieved.  Closer inspection of other engine components revealed a crack in the exhaust crossover passage on the bottom side of the intake manifold.

Exhaust gases entering the crankcase through the crack not only contaminate the engine oil, but the oil itself is super heated to the point where it no longer lubricates resulting in contact between the bearing and the crankshaft journal.

Pressurizing the crankcase with exhaust gases should also overwhelm the PCV system leading to excessive oil consumption or oil in the air cleaner.

For additional information see AERA Technical Bulletins: TB 519 &
SB 146

                                                                      The AERA Technical Committee

                                          Oil In The Cooling System On
                                           Ford 3.8L (232 CID) Engines

AERA member machine shops have reported multiple instances of vehicles with cooling systems contaminated by engine oil.

One possible cause cited in many of the reported cases was that the engines were permitted to freeze up during cold ambient temperatures.  Usually one or more of the core plugs was pushed out of the cylinder block, but the damage is not limited to that alone.  The ice inside of the cylinder block water jacket expands and partially crushes an oil gallery.

When the core plugs are replaced and the cooling system is refilled, oil finds its way into the radiator.  The cylinder block is no longer serviceable and must be replaced.

                                                                     The AERA Technical Committee

                         Intake Manifold Coolant & Vacuum Leaks On
                                Ford 5.0L, 5.0L HO and 5.8L Engines

Intake manifold coolant and vacuum leaks have been found to be quite common on Ford 5.0L, 5.0L HO (High Output) and 5.8L engines.  For this engine, following the proper intake manifold torque values and torque sequence is very critical.

Installation of the aluminum intake manifold should proceed as follows:

    Clean all gasket surfaces of debris and oil residue.

    Apply a 1/8 bead of silicone sealer in the 4 corners where the cylinder heads 
    meet the cylinder block (Figure 1).

    Install the intake manifold side and end gaskets and apply a 1/16 bead of 
    silicone sealer in the 4 joints formed by the gaskets.

    Mount the manifold and torque the bolts in sequence to 15-20 lbs.ft (Figure 2).

    Torque the bolts in sequence to 23-25 lbs.ft.

    After the engine has reached operating temperature, retorque the intake 
    manifold bolts to 23-25 lbs.ft.

                                                                                  The AERA Technical Committee

                                     Ignition Firing Order On
                            Ford 5.0L HO (High Output) Engines

There seems to be much confusion about the firing order on Ford 5.0L HO (High Output) engines. 

Contrary to the plain 5.0L engine, the HO (High Output) version uses the same firing order as the 5.8L engine.  This is probably the case because early 5.0L HO engines used a 5.8L marine camshaft.

The firing order for the standard 5.0L is: 1-5-4-2-6-3-7-8.  The firing order for the HO engine is: 1-3-7-2-6-5-4-8.  The rotor inside the distributor rotates counterclockwise on both engines (see illustration).

Using the plain 5.0L firing order on the HO engine does work, however the engines will have low vacuum and very poor idle.  At higher rpm it appears to smooth out, but is very low on horse power, not at all what the customer will expect from this potent power plant. 

                                                                        The AERA Technical Committee

                                       Mysterious Coolant Loss On
                                  1997-2000 Ford 4.0L VIN E Engines

The AERA Technical Committee offers the following information regarding coolant loss on 1997-2000 Ford 4.0L VIN E engines. The amount of loss reported varied depending on the driving habits of drivers. The area of coolant leakage has been in the exhaust port of the cylinder head. This engine is a V-6 SOHC design and either head may be suspect of leakage.

It has been reported the head casting temperature is a contributing factor on the amount of leakage. Short trip driving produces different amounts of loss than extended highway driving. Pressure testing suspect heads may not produce leakage until the head is heated. In these instances, a submergible type tester that has heated water in it is preferred. The vehicle diagnosis may be accomplished by loosening the exhaust manifold bolts on both heads and looking for coolant in the exhaust port. 

In most instances there is no evidence of moisture (coolant) coming out the tailpipe until the leak gets bad enough to leak all the time. The cracks in the exhaust port(s) leak coolant into the hot exhaust flow and almost all traces of coolant are removed by the catalytic converter. Using a fluorescent dye in the coolant may show the coolant trail when checked with a blacklight at the tail pipe opening.   

If the coolant leaks long enough an exhaust restriction may be created in the converter. It is suggested an engine exhaust backpressure be taken after this type of cylinder head failure. 

                                                                            The AERA Technical Committee

                                 Piston Caution For Standard Size Bore On
                                       1988-96 Ford 1.9L VIN J Engines

The AERA Technical Committee offers the following piston caution regarding standard size bore Ford 1.9L 1988-96 VIN J engines. Ford offers three different piston diameters to adjust piston to wall clearance.

When the measured piston to bore clearance is in the lower one third of the specified clearance .0012-.0028 (.3040 -.0711 mm) use a RED (smallest) color-coded piston. If the measured piston to bore clearance is in the middle of the specified clearance, use a BLUE color-coded piston. Finally, be aware that there is a .004 (.101 mm) oversize YELLOW piston available from Ford. Any combination of the above piston sizes may have been installed in the original production engine. If the pistons are being considered for reuse during engine disassembly, keep them in order and save time later.

Desired Piston Clearance .0012-.0028 (.030-.071mm)

Color Mark                  Diameter
Red                             3.224-3.225 (81.90-81.92 mm)
Blue                            3.225-3.226   (81.92-81.92 mm)
Yellow +.004             3.226-3.227   (81.94-81.96 (mm)

                                                                             The AERA Technical Committee

                                       Front End Engine Noise On
                                   1992-94 Ford VIN X 2.3L Engines

AERA members have reported front-end engine noise on 1992-94 Ford VIN X 2.3L engines. The noise has been described as a ticking or clanging coming from the front crankshaft on some vehicles. A loose center hub of the vibration damper pulley could cause this noise. 

Ford offers a replacement vibration damper pulley with a revised vibration damper pulley kit. The replacement parts kit can be purchased under Part #F6PZ-6312-AA. Ford also includes the following service procedure to change the revised parts. 

When replacement is needed on the vibration damper pulley is to be replaced, remove the vibration damper retaining bolt and vibration damper. If necessary use bearing puller T77F-4220-B or equivalent. The bolt and washer included in the vibration damper pulley kit must be used with a torque specification of 123-143 ft/lbs when securing the revised pulley to the crankshaft. Do not use the original bolt and washer. 

The vibration damper pulley kit, Part #F6PZ-6312-AA, includes the following: 

1-Crankshaft Pulley Assembly
1-Flatwasher: 14 X 14.7 X 6.35 mm
1-Hex Flange Bolt: M14 X 1.5 X 44.7 mm
1-Instruction Sheet

                                                                            The AERA Technical Committee