Ignition Coil and Iridium Spark Plugs for Lincoln Navigator (1998-1999) 5.4L

Direct-Replacement Ignition Coil and Iridium Spark Plug Kit for 1998-1999 Lincoln Navigator

What it Does: Restores factory ignition performance and delivers reliable spark energy across all 8 cylinders by replacing worn coil-on-plug packs and degraded plugs with high-dielectric assemblies and fine-wire iridium plugs.

The Stock Navigator Ignition Degradation

The first-generation Navigator's 5.4L Modular V8 relies on individual coil-on-plug (COP) units mounted deep within the cylinder head wells. Over time, persistent thermal cycling and underhood heat soak degrade the factory epoxy potting and internal copper windings, resulting in high internal resistance and micro-cracking in the secondary insulation. This causes high-voltage tracking, weak arc energy, intermittent misfires under heavy throttle load, rough idling, and catalytic converter damage from unburned fuel.

The Engineering Solution

This direct-fit kit pairs 8 heavy-duty coil-on-plug assemblies with 8 fine-wire iridium spark plugs to re-establish complete combustion. The coils feature premium high-conductivity copper windings, heat-resistant silicone boots, and corrosion-resistant blade terminals designed to withstand engine-bay heat without voltage drop. Matched with fine-wire iridium spark plugs that require lower firing voltage, this set ensures sustained spark stability, smoother cold starts, and consistent torque output under towing conditions.

Technical Specifications

Compatibility

• 1998 Lincoln Navigator Base 5.4L V8 (SOHC 2V Modular)
• 1999 Lincoln Navigator Base 5.4L V8 (SOHC 2V / DOHC 4V InTech Modular)

The Lincoln Durability Standard

Engineered for full-size luxury SUVs tasked with heavy passenger hauling and severe-duty towing, this ignition package delivers the rugged electrical reliability required to eliminate misfire codes and maintain maximum towing torque.