Ignition Coil and Iridium Spark Plugs for Cadillac Deville (2004-2005) 4.6L

Direct-Fit Ignition Coil and Iridium Spark Plug Kit for 2004-2005 Cadillac Deville

Primary Function: Completely refreshes the secondary ignition system to eliminate engine misfires, restore lost combustion efficiency, and stabilize idle quality across all eight cylinders.

The Stock Deville Thermal Fatigue and Dielectric Breakdown

The 4.6L Northstar engine operates under tight underhood packaging, subjecting factory coil packs to prolonged thermal stress and extreme heat-soak cycles. Over time, original coil insulation and internal epoxy potting degrade, developing micro-fractures that cause dielectric breakdown. This results in high-voltage arcing to the cylinder head rather than the plug gap, triggering P0300 misfire codes, rough idling, hesitation under load, and unburned fuel entering the catalytic converters.

The Engineering Solution

This comprehensive 8-cylinder ignition kit replaces degraded factory components with high-dielectric epoxy housings and premium high-conductivity internal copper windings for maximum secondary voltage output. Paired with laser-welded iridium spark plugs featuring ultra-fine center electrodes, this setup lowers ignition voltage requirements, resists electrode erosion, and ensures a clean, consistent spark flame kernel under high cylinder pressures and temperatures.

Technical Specifications

Compatibility

• 2004 Cadillac Deville Base 4.6L V8
• 2004 Cadillac Deville DHS 4.6L V8
• 2004 Cadillac Deville DTS 4.6L V8
• 2005 Cadillac Deville Base 4.6L V8
• 2005 Cadillac Deville DHS 4.6L V8
• 2005 Cadillac Deville DTS 4.6L V8

The Cadillac Refinement Standard

Engineered to deliver seamless power delivery and quiet operation, this matched coil and iridium plug kit restores the signature velvety-smooth V8 performance expected from a flagship Cadillac luxury sedan without check engine lights.