This procedure covers the removal and replacement of ignition coil packs on the 3.5L V6 EcoBoost engine in 2015-2020 Ford F-150 trucks.

Warnings

Tools required

Parts

• Ignition coil pack × 6 — Motorcraft DG-521 or equivalent

Preparation

1. Park vehicle on level surface and apply parking brake
2. Allow engine to cool completely (minimum 1 hour after operation)
3. Disconnect negative battery terminal and wait 2 minutes
4. Remove engine cover by pulling upward on cover - it is retained by grommets
5. Identify which coil(s) require replacement (coils numbered 1-3 passenger side front-to-rear, 4-6 driver side front-to-rear)

Procedure

1. 1

   Access the ignition coils
   With engine cover removed, locate the six ignition coils positioned on top of the valve covers. Each coil sits directly above its corresponding spark plug. Note the cylinder numbering: passenger side front-to-rear is 1-2-3, driver side front-to-rear is 4-5-6.
2. 2

   Disconnect coil electrical connector
   Press the locking tab on the electrical connector at the top of the coil pack and pull the connector straight up and away from the coil. Do not pull on the wiring harness itself. If connector is stuck, gently wiggle while pulling upward.
3. 3

   Remove ignition coil retaining bolt
   Using a 7mm socket with extension, remove the single bolt securing the ignition coil to the valve cover. Keep the bolt in a safe location for reinstallation.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
4. 4

   Extract the ignition coil
   Grasp the coil body firmly and pull straight upward with a twisting motion to break the seal. The coil boot extends down into the spark plug well. If resistance is felt, continue twisting gently while pulling - do not force. The coil should release with moderate effort.
5. 5

   Inspect spark plug well
   Use compressed air or a clean lint-free cloth to clean any debris from the spark plug well and valve cover area. Check for oil or coolant contamination in the well - if present, investigate source before continuing. Inspect the coil boot for tears, cracks, or carbon tracking.
6. 6

   Inspect and service spark plug (if needed)
   If replacing coil due to misfire or if spark plugs are near service interval, inspect the spark plug. Look for abnormal wear, fouling, or gap issues. If replacing spark plug, remove with spark plug socket, apply anti-seize to threads of new plug, and install to specification.
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
7. 7

   Prepare new ignition coil
   Remove new coil from packaging and inspect the boot for damage. Apply a thin coat of dielectric grease to the inside of the coil boot and around the spark plug terminal to prevent moisture intrusion and ensure proper electrical contact. Do not over-apply - excess grease can attract debris.
8. 8

   Install new ignition coil
   Align the coil with the spark plug well and push down firmly while twisting slightly to seat the boot onto the spark plug. The coil should slide down smoothly and sit flush against the valve cover mounting surface. Ensure the mounting hole in the coil aligns with the threaded hole in the valve cover.
9. 9

   Install coil retaining bolt
   Thread the 7mm retaining bolt by hand to avoid cross-threading, then tighten to specification using a torque wrench. Do not overtighten as this can crack the coil housing.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
10. 10

    Reconnect electrical connector
    Push the electrical connector onto the coil terminal until you hear and feel a positive click. Gently tug on the connector to verify it is fully locked in place. The connector should not pull off with light hand pressure.
11. 11

    Repeat for remaining coils
    If replacing multiple coils, repeat steps 2-10 for each coil requiring replacement. Work methodically to avoid mixing up connectors or hardware between cylinders.

Reassembly

1. Reinstall engine cover by aligning grommets with mounting posts and pressing down firmly until seated
2. Reconnect battery negative terminal
3. Clear any diagnostic trouble codes with scan tool if applicable

Verification

• Start engine and verify it runs smoothly without misfires or rough idle
• Listen for any unusual noises such as arcing or sparking sounds from coil area
• With engine running, verify no check engine light illumination
• Perform a test drive and confirm normal acceleration and power delivery
• If scan tool is available, monitor misfire counters to verify zero misfires on replaced coil cylinders

More procedures for this vehicle