What is a Ford Falcon EA-AU?

The EA (1988-1991), EB (1991-1993), ED (1993-1994), EF (1994-1996), EL (1996-1998), and AU (1998-2002) are six generations of the Ford Falcon built at Ford's Broadmeadows plant in Melbourne, Victoria. All share a common platform lineage and the 4.0-litre SOHC inline-six engine (3.9L in the EA). They were sold as sedans, wagons, and utes, with variants ranging from the base S/XT to the sporting XR6 and luxury Fairmont Ghia.

What engine does my Falcon have?

All EA-AU Falcons use a version of the Ford Australia inline-six:

• EA: 3.9L (3,947 cc) SOHC, single-point or multipoint injection, 135-145 kW
• EB-ED: 4.0L (4,016 cc) SOHC, multipoint injection, 152 kW
• EF: 4.0L SOHC, coil pack ignition, 164 kW
• EL: 4.0L SOHC, refined calibration, 164 kW (172 kW XR6)
• AU: 4.0L Intech SOHC with Variable Cam Timing (VCT), 157 kW (164 kW XR6)

The AU XR8 uses a 5.0L Windsor V8 (later 5.6L), which is a different engine entirely.

What is the difference between the EF and EL?

The EL (1996-1998) is an evolution of the EF (1994-1996). Key differences: the EL has revised exterior styling (new headlights, taillights, bumpers), improved interior materials, a better-balanced crankshaft, and refined engine calibration. The EL XR6 produces 172 kW versus the EF's 164 kW. Mechanically, most parts interchange between the two models. Many enthusiasts consider the EL the best of the SOHC Falcons.

What is Smartlock and why won't my car start?

Smartlock is Ford's engine immobiliser system, introduced on the EB Falcon. It uses a transponder chip in the ignition key that communicates with the Body Electronics Module (BEM). If the BEM doesn't recognise the key's signal, it cuts fuel delivery to the injectors, the engine will crank but not start. An exclamation mark below the handbrake warning light on the dashboard indicates a Smartlock lockout.

Common causes: flat battery, replacing the ECU or BEM without reprogramming, engine swap from a different vehicle, or a faulty key transponder. The fix requires reprogramming by a Ford dealer or auto electrician ($100-300), or installing a Smartlock bypass module ($50-100) which permanently disables the system.

What is the TFI module and why does it fail?

The Thick Film Ignition (TFI) module is used on EA-ED Falcons. It's mounted on the distributor and controls ignition timing. The TFI module is notorious for heat-related failure, the engine suddenly cuts out while driving and won't restart until it cools down. This is a design flaw: the module sits directly on the engine, absorbing heat from both the engine and exhaust manifold. Replacement costs $80-150. Carry a spare at all times. The EF and later models replaced the TFI with a more reliable coil pack system.

Can I swap engines between different E-series models?

Yes, with caveats. The 4.0L SOHC engine will physically fit across all EA-AU models (and even the XG/XH utility). However:

• You must use the intake manifold, sensors, and wiring harness from the destination car, not the donor engine.
• Distributor-equipped motors (EA-ED) and coil pack motors (EF-EL) have different ignition systems, swap the complete ignition system with the manifold.
• The distributor drive gear on the auxiliary shaft may differ between models, swap the gear if changing distributor types, or you risk damaging the aux shaft.
• Smartlock (EF onwards): use the destination car's ECU and BEM, or deal with immobiliser issues.
• The AU Intech VCT engine can go into earlier cars but requires the AU ECU and wiring for VCT to function.
• The AU bottom end (sump bolted to main caps) is the strongest SOHC bottom end and is popular for performance builds in earlier cars.

What fuel should I use?

All EA-AU models run on 91 RON regular unleaded fuel. Using 95 RON premium provides a small improvement in performance and fuel economy due to slightly advanced ignition timing. 98 RON is unnecessary for stock engines and offers no benefit beyond 95. E10 is acceptable but may cause fuel system issues on cars with old rubber fuel lines, the ethanol attacks aged rubber.

My AU Falcon is stuck in 3rd gear, what's wrong?

This is limp mode. The automatic transmission control module has detected a fault and locked the transmission in 3rd gear as a protective measure. The most common fault code is P0748 (line pressure control electrical). Causes include: a faulty transmission solenoid, wiring harness damage, transmission control module failure, or genuinely worn internal components. Start by scanning for codes with a diagnostic tool. Sometimes clearing the code and cycling the ignition resolves it temporarily. A persistent limp mode requires transmission inspection by a specialist.

How do I read fault codes on my EA-EL Falcon?

EA-EL Falcons use Ford's EEC-IV/EEC-V diagnostic system. To read codes: (1) Locate the diagnostic connector (usually near the left strut tower or under the dash). (2) Short the far-left top pin to the far-left bottom pin with a wire or paper clip. (3) Turn the ignition to ON (don't start the engine). (4) Count the flashes on the check engine light, codes are given as three-digit numbers with pauses between digits. For example, 634 = 6 flashes, pause, 3 flashes, pause, 4 flashes. Common codes: 636 (transmission oil temp), 634 (gear selector sensor), 786 (oxygen sensor). Put the engine in diagnostic mode by shorting the pins and starting the engine to access additional tests.

What are the best first modifications?

The widely accepted modification path for the SOHC six:

1. Exhaust system: 2.5-inch mandrel-bent exhaust with extractors (Pacemaker or JMM). Budget $550-900. Expect 5-15 kW gain.
2. Performance camshaft: Wade 1004, Wade 977B, Wade 1636, or Crow billet cam. Budget $300-600 plus fitting. Expect 5-30 kW gain depending on profile. Extractors should be fitted first for maximum cam benefit. Shims may be needed for regrind cams (Crow billet cams don't need shims).
3. Air intake: EL GT snorkel (bolt-on swap for EF-EL, $30 from Ford). K&N or BMC panel filter. Custom mandrel-bent intake pipe for EF-EL ($150-250).
4. Head work: Port and polish, larger valves, shaved head for compression increase. Budget $400-2,000 depending on scope.
5. Engine management: J3 chip (EF-EL) or aftermarket ECU for more aggressive builds.

The exhaust and cam combination is the most cost-effective path to meaningful power gains.

Can I put Barra injectors in my SOHC motor?

Yes. Barra injectors (290 cc) will physically fit SOHC Falcon fuel rails. Stock SOHC injectors are approximately 220 cc. The larger Barra injectors provide more headroom for modified engines. On a stock engine without a tune, the car may run slightly richer at idle but will generally function. For best results, get a tune to take advantage of the increased fuel delivery. This is a popular modification for burnout and track cars.

What is the AU bottom end and why is it special?

The AU Intech engine has a sump that bolts to the main bearing caps (similar to the Barra's cross-bolted design), making the bottom end significantly stiffer and stronger than earlier SOHC engines. The AU also uses a slightly longer connecting rod than the EF/EL. For this reason, the AU bottom end is the preferred choice for high-power SOHC builds, particularly turbocharged or supercharged applications. A common performance combination is an AU bottom end with an EF ported head, performance cam, and aftermarket engine management.

What's the difference between the clutch fan and thermo fans?

EA-ED models use a viscous clutch fan mounted to the water pump. It's always spinning (faster when hot) and robs engine power, particularly noticeable at low speeds and idle. EF-EL models switched to electric thermo fans that only run when coolant reaches a set temperature. Converting EA-ED models to EF/EL twin thermo fans is a popular modification. You can buy a conversion kit from Battens Performance, or DIY it with a Davies Craig thermo-switch kit and EF/EL fans from a wrecker ($180 from Ozeparts).

How long do these engines last?

With regular oil changes and basic maintenance, the 4.0L SOHC inline-six routinely exceeds 300,000 km. Many taxi and fleet examples have recorded over 500,000 km on original engines. The key to longevity is oil change frequency (every 7,500 km or sooner), cooling system maintenance (thermostats, hoses, and coolant changes), and addressing minor issues before they become major failures.

Are parts still available?

Yes. EF-AU parts are plentiful from wreckers and aftermarket suppliers. EA-ED parts are becoming scarcer but are still available through specialist Ford wreckers and online communities. Most mechanical components (engine parts, suspension, brakes) interchange across the EA-AU range, making sourcing easier. Aftermarket companies like JMM, Wade Cams, Pacemaker, and Crow Cams continue to support the platform. FordMods.com remains the primary online resource for technical information and parts sourcing.

Is the AU Falcon really that ugly?

Beauty is subjective. The AU's "New Edge" styling was controversial at launch and polarised buyers. Many initially hostile owners have come to appreciate the AU's distinctive appearance, and clean examples are becoming valued for their uniqueness. The AU3 received minor styling refinements that softened the most controversial elements. Inside, the AU is a better car than the EL, the cabin is quieter, the seats are more comfortable, and the VCT engine is more responsive. Judge the AU on its driving merits, not just its looks.