Problem Statement

Ford Explorers from the year 2004, like many vehicles of the time, can suffer from a deteriorated ignition coil pack. A faulty ignition coil can often lead to misfires, rough idling, poor fuel economy, or even a non-starting vehicle. This guide will take you through the steps necessary to diagnose and replace your ignition coil pack.

Tools Required

• Socket Set
• T-25 Torx Bit
• Ignition Coil Puller
• New Ignition Coil Pack
• Dielectric Grease
• Gloves
• Safety Glasses

Diagnostic Process

1. Start by checking for engine trouble codes. If you notice codes P0351-P0356, this could indicate a faulty ignition coil pack.
2. Visually inspect the ignition coil pack area for cracks, burns, or other damages. Also, inspect the electrical connectors for any corrosion or looseness.
3. Using engine diagnostic tools like spark testers or multimeters, you can check for proper spark generation from the coil pack.

Replacement Procedure

1. Locate the ignition coil pack. It is typically placed on top of the engine in a Ford Explorer.
2. Disconnect the electrical connector to the ignition coil pack.
3. Using your socket set and T-25 Torx Bit, remove the bolts securing the ignition coil pack.
4. Using the ignition coil puller, remove the failed ignition coil pack from the vehicle.
5. Before installing the new coil pack, apply a small amount of dielectric grease to the boot. This ensures a good electrical connection and prevents arcing.
6. Install the new ignition coil pack into the vehicle. Ensure that it snaps correctly into place.
7. Replace the bolts and reconnect the electrical connector. Ensure all bolts are tightened adequately and the connector is secure.
8. Clear any existing diagnostic trouble codes, then start the vehicle and check for any new codes. If no new codes appear and the vehicle runs smoothly, the replacement was successful.

Tip: Always disconnect the battery when working on your vehicle's electrical system. Also, use gloves and safety glasses for your protection.

Potential Pitfalls

• Not cleaning the connectors could lead to a bad connection with the new coil pack.
• Cracked or brittle rubber boots can cause misfires and should also be replaced.
• Not applying dielectric grease can cause an electrical leak.

Tips for Success

• Never assume the problem lies solely with the ignition coil pack. Always perform a thorough diagnostic before diving into the replacement job.
• Ensure the replacement coil pack is compatible with your vehicle make, model, and year.
• If the engine misfire problems remain after coil pack replacement, consider checking the spark plugs and wires, as they could also be faulty.