Replace all eight spark plugs on the 5.0L V8 Coyote engine, including removal of ignition coils and proper gap verification.

Warnings

Tools required

Parts

• Spark plugs - Motorcraft SP-520 or equivalent × 8 — SP-520

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery terminal to prevent accidental starter engagement
3. Park vehicle on level surface and engage parking brake
4. Verify you have the correct spark plugs for this application (Motorcraft SP-520 recommended)
5. Gap all new spark plugs to 0.051-0.057 inches (1.30-1.45mm) before installation

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly and pull upward to disengage the mounting grommets. The cover is held by push-in grommets and does not require tools for removal. Set aside in a clean area.
2. 2

   Locate and access ignition coils
   Identify all eight ignition coils mounted directly above each spark plug. On the 5.0L Coyote, four coils are on each cylinder bank. Clear any debris or wiring harnesses that may obstruct access to the coil mounting bolts.
3. 3

   Disconnect ignition coil electrical connectors
   Press the release tab on each coil connector and pull straight up to disconnect. Work on one coil at a time to avoid mixing up cylinder positions. Note the routing of any wiring that needs to be moved aside.
4. 4

   Remove ignition coil mounting bolts
   Using an 8mm socket, remove the single bolt securing each ignition coil. Keep bolts organized by cylinder location. The bolts are relatively short and may require a short extension to access.
   ℹ️Some coils may be tight in their bores due to heat cycling. Wiggle gently while pulling to avoid breaking the coil boot.
   Torque spec

   Ignition Coil Bolt14 Nm (10 lb-ft)
5. 5

   Extract ignition coils
   Grasp each coil firmly and pull straight up with a slight twisting motion to break the seal. The coil boot is seated in the spark plug tube. Inspect each boot for tearing or deterioration and replace if damaged.
6. 6

   Clean spark plug tubes
   Use compressed air to blow out any debris, dirt, or oil from each spark plug tube. Ensure the area around the spark plug is completely clean to prevent contamination from falling into the cylinder when the plug is removed. A vacuum can also be used to extract debris.
   ⚠Never proceed with spark plug removal if debris is present in the tube. Contamination entering the cylinder can cause engine damage.
7. 7

   Remove old spark plugs
   Using a 5/8 inch spark plug socket with extension, carefully loosen each spark plug by turning counterclockwise. Once loose, continue to unthread by hand using the socket to prevent cross-threading. Remove all eight plugs and inspect electrodes and insulators for wear, fouling, or damage patterns.
8. 8

   Inspect spark plug condition
   Examine each old plug for abnormal wear, carbon buildup, oil fouling, or electrode erosion. Consistent abnormal wear patterns across multiple cylinders may indicate underlying engine issues that should be addressed. Normal plugs will have light tan or gray deposits.
9. 9

   Prepare new spark plugs
   Verify each new spark plug gap is set to 0.051-0.057 inches using a gap tool. Apply a small amount of anti-seize compound to the threads of each plug, coating only the first 2-3 threads. Do not over-apply as excess can contaminate the electrode.
   ℹ️The Coyote engine has aluminum heads. Anti-seize is essential to prevent galling and seizing.
10. 10

    Install new spark plugs
    Carefully thread each new spark plug by hand into its cylinder, turning clockwise. Thread at least 3-4 full turns by hand to ensure proper alignment and prevent cross-threading. If resistance is felt, remove and restart. Once hand-tight, use the torque wrench and spark plug socket to tighten to specification.
    ⚠️Never force a spark plug. Cross-threading will destroy aluminum head threads requiring expensive repair.
    Torque spec

    Spark Plug25 Nm (19 lb-ft)
11. 11

    Apply dielectric grease to coil boots
    Apply a small amount of dielectric grease to the inside of each ignition coil boot. This aids in future removal and prevents moisture intrusion. Use sparingly as excess can attract dirt.
12. 12

    Reinstall ignition coils
    Align each coil with its spark plug tube and push down firmly with a twisting motion until the coil is fully seated on the spark plug. The coil should sit flush with the valve cover surface. Install and hand-thread each mounting bolt before torquing.
    Torque spec

    Ignition Coil Bolt14 Nm (10 lb-ft)
13. 13

    Reconnect electrical connectors
    Push each coil connector onto its corresponding coil until you hear and feel a positive click. Gently tug on each connector to verify it is locked in place. Ensure wiring is routed properly and not pinched or stretched.
14. 14

    Reinstall engine cover and reconnect battery
    Align the engine cover grommets with their mounting posts and press down firmly until all grommets are seated. Reconnect the negative battery terminal and ensure it is tight.

Reassembly

1. Double-check that all eight ignition coil connectors are fully seated and locked
2. Verify engine cover is properly seated on all mounting grommets
3. Ensure no tools or parts have been left in the engine bay

Verification

• Start the engine and listen for smooth idle with no misfires or rough running
• Allow engine to reach operating temperature and verify no check engine light illuminates
• Perform a test drive and confirm smooth acceleration with no hesitation or misfires under load
• Use a scan tool to verify no misfire codes are present after test drive

More procedures for this vehicle