This procedure covers the inspection and replacement of ignition coil boots (note: the 3.5L EcoBoost uses coil-on-plug design with no traditional spark plug wires). The procedure includes removing ignition coils to access and service the coil boots.

Warnings

Tools required

Parts

• Ignition coil boots (set of 6) × 1 — Motorcraft DG-511 or equivalent
• Spark plugs (if replacement needed) × 6 — Motorcraft SP-534 (Iridium)

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery terminal and wait 2 minutes
3. Remove engine cover by pulling upward on front and rear clips

Procedure

1. 1

   Locate and access ignition coils
   Identify all six ignition coils on top of the engine. Three coils are located on each cylinder bank. Note their positions for proper reinstallation.
2. 2

   Disconnect ignition coil electrical connectors
   Press the locking tab on each coil electrical connector and pull straight back to disconnect. Do not pull on the wires themselves. Disconnect all six coil connectors.
   ⚠Pull on the connector body only, not the wiring harness, to prevent wire damage.
3. 3

   Remove ignition coil mounting bolts
   Using a 7mm socket with extension, remove the single mounting bolt from each ignition coil. Keep bolts organized for reinstallation.
   Torque spec

   Ignition Coil Bolt12 Nm (9 lb-ft)
4. 4

   Extract ignition coils
   Grasp each ignition coil firmly and pull straight up with a twisting motion to break the seal. If coils are stuck, gently twist while pulling. Remove all six coils and set aside in order.
   ⚠Coils may be tight due to heat cycling. Do not pry against coil body as this may crack the housing.
5. 5

   Clean spark plug wells
   Use compressed air or a shop vacuum to remove any debris, dirt, or oil from the spark plug wells. Ensure wells are completely clean before proceeding. Inspect for oil contamination which may indicate valve cover gasket leaks.
   ℹ️Oil in spark plug wells indicates valve cover gasket failure and should be addressed to prevent ignition coil damage.
6. 6

   Inspect or replace ignition coil boots
   Remove the old rubber boots from the bottom of each ignition coil. Inspect for cracks, tears, or carbon tracking. Replace boots if damaged or as preventive maintenance. Clean the coil terminals if reusing boots.
7. 7

   Apply dielectric grease to new boots
   Apply a small amount of dielectric grease inside each new ignition coil boot. Install the new boots onto the bottom of each ignition coil, ensuring they are fully seated. Apply a thin coat of dielectric grease inside the boot opening.
   ℹ️Dielectric grease prevents moisture intrusion and ensures proper electrical connection while allowing easy future removal.
8. 8

   Inspect spark plugs (optional)
   If desired, use a spark plug socket to remove spark plugs for inspection. Check electrode wear and gap. Replace if electrodes are worn, gap is incorrect, or plugs have over 60,000 miles. If replacing, gap new plugs to specification before installation.
   Torque spec

   Spark Plug23 Nm (17 lb-ft)
9. 9

   Reinstall ignition coils
   Align each ignition coil over its corresponding spark plug. Push down firmly with a slight twisting motion until the coil boot seats fully on the spark plug. Ensure coils are fully seated before installing bolts.
   ⚠Coils must be fully seated to ensure proper electrical connection. Partially seated coils will cause misfires.
10. 10

    Install and torque coil mounting bolts
    Install the mounting bolt on each ignition coil. Torque each bolt to specification using a torque wrench. Work in a consistent pattern across both banks.
    Torque spec

    Ignition Coil Bolt12 Nm (9 lb-ft)
11. 11

    Reconnect electrical connectors
    Reconnect the electrical connector to each ignition coil by pushing firmly until the locking tab clicks into place. Gently tug on each connector to verify it is locked.
12. 12

    Reinstall engine cover and reconnect battery
    Position the engine cover and press down firmly on all mounting points until the clips engage. Reconnect the negative battery terminal.
    Torque spec

    Engine Cover Clips3 Nm (2 lb-ft)

Reassembly

1. Ensure all ignition coil electrical connectors are fully locked in place
2. Verify engine cover is properly seated on all mounting clips
3. Double-check that all six ignition coil mounting bolts are installed and torqued

Verification

• Start the engine and verify smooth idle with no misfires or rough running
• Check for diagnostic trouble codes using an OBD-II scanner - there should be no ignition-related codes
• Listen for any unusual clicking or arcing sounds from the ignition coils during engine operation
• Test drive the vehicle and confirm proper acceleration with no hesitation or misfire conditions

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