What are the symptoms of a faulty ignition coil in the Ford Explorer Sixth Generation?

1. Engine Misfire

• Symptoms: You may notice your engine stumbling or shaking during acceleration. The vehicle might exhibit uneven power delivery, particularly under load.
• Diagnosis: Use an OBD-II scanner to check for misfire codes (P0300-P0306).

2. Reduced Engine Performance

• Symptoms: There may be a noticeable decrease in engine power, especially when attempting to accelerate. The vehicle may feel sluggish.
• Diagnosis: Test drive the vehicle to assess performance. Monitor throttle response and power under acceleration.

3. Rough Idle

• Symptoms: The engine may idle roughly or vibrate. You might experience fluctuations in RPM at a stop.
• Diagnosis: Observe the RPM gauge and listen for irregular engine sounds while idling.

4. Poor Fuel Economy

• Symptoms: A faulty ignition coil can lead to incomplete combustion, resulting in reduced fuel efficiency.
• Diagnosis: Keep track of fuel consumption and mileage over a period of time to see if there’s a significant decrease.

5. Check Engine Light

• Symptoms: The Check Engine Light (CEL) may illuminate on the dashboard.
• Diagnosis: Use an OBD-II scanner to retrieve fault codes associated with ignition coil issues.

6. Hard Starting or No Start

• Symptoms: Difficulty starting the engine or a complete failure to start can occur.
• Diagnosis: Listen for the engine cranking and check for fuel delivery and battery condition.

Tools Required

• OBD-II Scanner
• Multimeter
• Screwdrivers
• Ratchet and socket set
• Torque wrench
• Ignition coil tester (optional)

Step 1: Scan for Trouble Codes

1. Connect the OBD-II scanner to the vehicle’s diagnostic port.
2. Retrieve and note any error codes related to ignition misfires (P0300 series).
3. Clear the codes and take the vehicle for a test drive to see if they return.

Step 2: Visual Inspection

1. Open the hood and locate the ignition coils (usually on top of the engine).
2. Check for signs of damage, such as cracks, corrosion, or burnt connections.
3. Inspect the wiring harness for signs of wear or damage.

Step 3: Measure Coil Resistance

1. Disconnect the ignition coil connector.
2. Set a multimeter to the resistance (ohms) setting.
3. Measure the primary and secondary resistance:
   • Primary: Connect the multimeter leads to the coil terminals (consult the service manual for specific values).
   • Secondary: Measure between the coil terminal and the high voltage output terminal.
4. Compare readings to manufacturer specifications. If readings are outside specifications, the coil may be faulty.

Step 4: Test Spark Output

1. Use an ignition coil tester or a spark plug tester to check for spark.
2. Remove a spark plug from one cylinder.
3. Connect the tester to the ignition coil and crank the engine.
4. Observe if a strong spark is produced. Weak or no spark indicates a faulty coil.

Repair Instructions

Step 1: Replace the Ignition Coil

1. Preparation: Gather new ignition coils that match OEM specifications.
2. Disconnect the Battery: Disconnect the negative terminal from the battery to prevent electrical shocks.
3. Remove the Old Coil:
   • Remove any components obstructing access to the ignition coil (intake manifold, engine covers, etc.).
   • Unscrew the bolts securing the ignition coil.
   • Carefully pull the coil out of the cylinder head.
4. Install the New Coil:
   • Apply a small amount of dielectric grease to the terminal of the new coil.
   • Insert the new coil into the cylinder head and torque the bolts to the manufacturer specifications.
   • Reconnect the electrical connector securely.
5. Reassemble Components: Replace any components removed during the disassembly.
6. Reconnect the Battery: Reconnect the negative terminal of the battery.

Step 2: Test the Vehicle

1. Start the engine and check for any warning lights on the dashboard.
2. Monitor engine performance, idle quality, and response during acceleration.
3. Use the OBD-II scanner to ensure no codes are present.

Step 3: Final Check

1. Take the vehicle for a test drive to confirm that the symptoms have been resolved.
2. Monitor fuel economy and engine performance over the next few days.

By following these steps, you can accurately diagnose and repair a faulty ignition coil in a Ford Explorer Sixth Generation.