This procedure covers the removal and replacement of ignition coil packs on the 3.5L EcoBoost V6 engine in a 2021-2024 Ford F-150.

Warnings

Tools required

Parts

• Ignition coil pack × 1 — Motorcraft DG-521 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 30 minutes after operation)
3. Identify which coil pack needs replacement based on cylinder number from diagnostic codes
4. Open hood and locate the engine cover (may have 'EcoBoost' branding)
5. Gather all tools and parts before beginning

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly and pull upward to disengage the retention grommets. The cover is not bolted and uses push-in mounting points. Set cover aside in a clean area.
2. 2

   Locate target ignition coil
   Identify the coil pack corresponding to the cylinder requiring service. Cylinders are numbered 1-3 on the passenger side (front to rear) and 4-6 on the driver side (front to rear). Each coil has an electrical connector on top and sits directly in the spark plug well.
3. 3

   Disconnect coil electrical connector
   Press down on the connector lock tab while pulling the connector straight up and away from the coil pack. Do not pull on the wiring harness. The connector may be stiff due to seal friction. Gently wiggle if needed.
4. 4

   Remove coil pack retaining bolt
   Using a 10mm socket with extension, remove the single bolt securing the coil pack. The bolt may remain in the coil pack body when loosened. Keep bolt in a safe location for reinstallation or replacement.
5. 5

   Extract coil pack from spark plug well
   Grasp the coil pack body firmly and pull straight up with steady pressure. The coil may resist due to the rubber boot seal on the spark plug terminal. Do not twist excessively. If stuck, gently rotate 1/4 turn back and forth while pulling upward. Inspect the rubber boot for tears or damage.
   ⚠Do not use excessive force or pry tools, as this may damage the spark plug well or break the coil boot inside the well.
6. 6

   Clean spark plug well
   Use compressed air or a shop vacuum to remove any debris, dirt, or oil from the spark plug well. Ensure no foreign material will fall into the cylinder. Inspect for oil contamination in the well, which may indicate a valve cover gasket leak requiring separate attention.
   ⚠Never allow debris to enter the combustion chamber. A small piece of dirt can cause severe engine damage.
7. 7

   Inspect spark plug condition (optional)
   If you are replacing the coil due to a misfire and have a spark plug socket available, consider removing and inspecting the spark plug. Look for fouling, unusual wear, or damage. If spark plug shows carbon buildup or oil fouling, replacement is recommended. Check spark plug gap if reusing.
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
8. 8

   Prepare new coil pack
   Remove new coil pack from packaging. Inspect the rubber boot for any damage. If desired, apply a thin coating of dielectric grease to the inside of the rubber boot where it contacts the spark plug terminal. This aids future removal and prevents moisture intrusion.
9. 9

   Install new coil pack
   Align the new coil pack with the spark plug well and push down firmly until the coil seats completely. The rubber boot must fully engage the spark plug terminal. You should feel the coil bottom out with the mounting surface flush against the cylinder head.
10. 10

    Install and torque coil pack bolt
    Insert the coil pack retaining bolt and hand-tighten. Using a torque wrench, tighten the bolt to specification. Do not over-torque as this can crack the coil pack housing.
    Torque spec

    Ignition Coil Bolts8 Nm (6 lb-ft)
11. 11

    Reconnect electrical connector
    Align the electrical connector with the coil pack terminal and push down firmly until you hear and feel a distinct click. Gently tug upward on the connector to verify it is fully locked in place.
12. 12

    Reinstall engine cover
    Align the engine cover mounting grommets with their corresponding posts on the engine. Press down firmly on each mounting point until all grommets are fully seated. Ensure cover is secure and level.

Reassembly

1. Double-check that the electrical connector is fully seated and locked
2. Verify engine cover is properly installed on all mounting points
3. If diagnostic trouble codes were present, they may need to be cleared with a scan tool after confirming repair

Verification

• Start the engine and listen for smooth idle with no misfires
• Verify the check engine light does not illuminate or returns to normal operation
• If a scan tool is available, check for active misfire codes on the repaired cylinder
• Test drive the vehicle under light acceleration to confirm smooth operation and no hesitation
• Re-scan for codes after 20-30 miles of driving to ensure misfire has not returned

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