Marsram Ignition Coil Pack FD508 for 5.4L V8 Ford F-150 / Expedition — Direct Replacement, Straight Black Boot

This ignition coil pack is built as a one-to-one replacement for FD508-style coils found on many mid-2000s Ford vehicles. It delivers consistent secondary voltage for each cylinder to help the engine fire smoothly and reduce misfires when matched to the correct engine type. Before purchasing, verify the coil’s black straight boot design and your vehicle’s engine size — this coil is not compatible with V10 engines or coils that use brown or curved boots.

How do I know if the FD508 fits my truck or SUV?

Fitment depends on engine displacement and the coil’s physical appearance. This FD508 is intended for 5.4L V8 engines on specific model years and some 4.6L V8 applications; it replaces numerous OEM numbers listed for the FD508 family. Always compare the connector, mounting points, and straight black boot style to your original coil before ordering.

• Compatible vehicles include 2004–2008 Ford F-150 5.4L V8 and 2005–2008 Expedition 5.4L V8.
• Also fits Lincoln Navigator, Mark LT, Ford Super Duty trucks, and select Mustang 5.4L V8s.
• Some 2006–2008 Explorer and Mercury Mountaineer models with 4.6L V8 may use equivalent coils; confirm with parts finder.
• Not compatible with V10 engines or coils featuring brown/curved boots.

What symptoms indicate a failing ignition coil pack?

Worn coils commonly cause rough idling, intermittent misfires, or a loss of power during acceleration. The vehicle may illuminate the check engine light and store codes related to misfires (P030x). Replacing an aged coil with a correct FD508 unit can often clear those symptoms when they originate from ignition failure.

• Persistent engine misfire codes (P0300–P0308) under load or at idle.
• Rough running, stalling, or hesitation during acceleration.
• Reduced fuel economy due to incomplete combustion.
• Visible arcing or cracked coil boots on inspection.

How easy is installation and what tools are required?

Installation is straightforward for anyone comfortable with basic automotive repairs. The coil mounts directly to the valve cover and plugs into the factory wiring harness; expect about 20–45 minutes for one coil depending on engine bay access. Use hand tools and follow torque specs to avoid over-tightening the mounting bolt.

• Tools: ratchet, socket set, extension, and dielectric grease for boots.
• Disconnect battery negative before starting to avoid shorts.
• Inspect spark plugs and wiring while the coil is removed; replace as needed.
• Confirm straight black boot orientation and secure connector clips on reassembly.

What warranty and part numbers does this Marsram coil replace?

The FD508 coil carries a 1-year warranty backed by Marsram quality testing. It replaces many OEM and aftermarket numbers in the FD508 family, simplifying cross-reference when sourcing parts for repairs.

• Replaces FD508 and related numbers like C1541, C1659, UF537, DG511 and others.
• Warranty: 1-year limited coverage against manufacturing defects.
• Recommended: use parts finder to confirm exact match for your VIN and engine.

Who is this for: This Marsram FD508 ignition coil pack is suited for owners and independent mechanics performing maintenance or repair on mid-2000s Ford, Lincoln, and Mercury V8 engines — especially 5.4L applications. Choose this unit if you need a cost-effective, warranty-backed replacement that matches OEM mounting and connector styles; avoid it if your vehicle uses V10 engines or coils with non-straight brown/curved boots.