This procedure covers the removal and replacement of a single ignition coil on the 3.5L EcoBoost V6 engine, including access through the engine cover and proper reconnection.

Warnings

Tools required

Parts

• Ignition coil × 1 — Motorcraft DG-520 or equivalent
• Spark plug (if damaged or at service interval) × 1 — Motorcraft SP-546 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure engine is completely cool to the touch
3. Disconnect negative battery terminal and wait 2 minutes for capacitor discharge
4. Identify which cylinder has the failed coil (cylinder numbering: passenger side front to rear 1-2-3, driver side front to rear 4-5-6)

Procedure

1. 1

   Remove engine cover
   Remove the plastic engine cover by pulling upward firmly on the front edge, then lifting the rear. The cover is retained by grommets on posts; no tools required. Set cover aside in clean area.
2. 2

   Access ignition coil
   Locate the ignition coil for the affected cylinder. If accessing coils on the driver side (cylinders 4-5-6), you may need to remove or reposition wiring harnesses or breather hoses for better access. Use care not to damage clips or connectors.
3. 3

   Disconnect coil electrical connector
   Press the locking tab on the ignition coil electrical connector and pull straight up to disconnect. Do not pull on the wiring; grasp only the connector body. Inspect connector and coil boot for oil contamination which may indicate valve cover gasket leak.
4. 4

   Remove ignition coil bolt
   Using an 8mm socket with extension, remove the single bolt securing the ignition coil to the valve cover. Keep the bolt in a safe place for reinstallation.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
5. 5

   Extract ignition coil
   Grasp the ignition coil body firmly and pull straight up with a twisting motion to break the seal. The coil boot extends deep into the spark plug well. If resistance is encountered, twist gently while pulling; do not pry or bend the coil.
6. 6

   Clean spark plug well
   Use compressed air to blow out any debris from the spark plug well before installing the new coil. Ensure no dirt, oil, or foreign material remains that could contaminate the spark plug or new coil boot. Inspect the spark plug if visible.
   ⚠Debris in the spark plug well can cause misfires or damage; ensure well is completely clean and dry
7. 7

   Inspect and prepare new coil
   Inspect the new ignition coil boot for damage and verify correct part number matches the original. Apply a thin coating of dielectric grease to the inside of the coil boot to aid installation and future removal. Do not use excessive grease.
8. 8

   Install new ignition coil
   Align the new ignition coil with the spark plug well and valve cover bolt hole. Press down firmly with a slight twisting motion until the coil seats fully against the valve cover. The coil should sit flush with no gap.
9. 9

   Install and torque coil bolt
   Thread the ignition coil bolt by hand to prevent cross-threading, then torque 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 ignition coil terminal until you hear and feel a distinct click indicating the locking tab has engaged. Gently tug on the connector to verify it is locked in place.
11. 11

    Reinstall engine cover
    Align the engine cover grommets with the mounting posts on the engine. Press down firmly on all mounting points until the cover seats completely. Ensure all grommets are properly engaged.
12. 12

    Reconnect battery and clear codes
    Reconnect the negative battery terminal. Start the engine and verify smooth operation with no misfires. Use a scan tool to clear any stored misfire codes. The engine may run slightly rough for 10-15 seconds while the ECM relearns.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify engine cover is properly secured on all mounting points
3. Check that no tools or parts were left in the engine compartment

Verification

• Start engine and verify it runs smoothly without misfires or rough idle
• Use scan tool to confirm no active misfire codes for the replaced cylinder
• Rev engine to 2000-3000 RPM and verify smooth operation under load
• Perform a short test drive to confirm normal acceleration and no check engine light

More procedures for this vehicle