Autoexact Ignition Coil Packs FD504

Highlights

If you’re trying to address a rough-running engine without sourcing coils one at a time, this eight-piece FD504 set is designed for selected Ford, Mercury, and Lincoln applications with 4.6L or 5.4L V8 engines. It’s intended as a replacement for compatible ignition coils, not a universal fix for every misfire or hard start.

The set includes eight coils, which can make a full-set replacement more convenient than changing one coil now and tracking down others later. The coils are described as direct-fit plug-in replacements, with green dielectric grease applied at the factory. That may simplify installation, but the vehicle’s exact fitment still matters more than the broad model list.

Fit and sizing

Listed applications include the 2000–2010 F-150 with a 4.6L engine, the 1997–2003 F-150 with a 5.4L, and the 1999–2016 E-350 Super Duty with a 5.4L. Other stated applications include the 1997–2004 Expedition with a 5.4L, 1999–2004 F-250 Super Duty with a 5.4L, and selected Grand Marquis, Town Car, Crown Victoria, and E-250 models with 4.6L engines. These are application-specific ranges, not confirmation that every trim or engine configuration in those years is compatible.

Keep in mind that the listing calls for checking year, make, model, and engine before ordering. Compare the original coil’s connector, boot length, and shape as well, a similar-looking part is not enough to establish a match. The set references FD504 and DG508, among other replacement numbers.

Tips for day-to-day use

If a compatible vehicle has a misfire, rough idle, hesitation, vibration, difficult starts, or a check-engine light, a weak coil could be one cause—but those symptoms alone don’t identify the failed part. A technician’s diagnosis can help avoid replacing all eight coils when the problem lies elsewhere. If you’re already planning a full replacement, the eight-pack keeps the parts together, for one confirmed failed coil, buying only the needed part may suit the repair better.

Before installation, compare each new coil with the original and confirm the connector and mounting position. For example, with the engine off, you can line up an old coil and its replacement to check the plug and boot before fitting the new part. The product is described as needing no modifications on compatible applications, but that depends on a correct match.

Practical doubts

Does the package include eight coils? Yes. The listing describes an eight-coil replacement set for compatible V8 applications.

Is dielectric grease included? The coils are described as factory pre-lubricated with green dielectric grease.

What support is stated? The listing specifies a two-year warranty and lifetime support for fitment and installation questions.

Should you buy it?

It suits you if you’ve confirmed that your vehicle’s year, engine, connector, and original coil match the listed FD504 applications and you want a complete eight-coil set. It also makes sense when replacing coils as a group is preferable to handling separate parts over multiple repairs. You may want to skip it if you need only one coil, can’t verify the exact application, or are treating symptoms without confirming that the ignition coil is the cause. The fitment details are the deciding factor here, not the broad Ford, Mercury, or Lincoln name alone.