Spark Plugs - V8

This procedure covers the removal and replacement of all eight spark plugs on the 5.0L Coyote V8 engine, including removal of ignition coils and engine covers.

Warnings

Tools required

Parts

• Spark plugs - Motorcraft SP-534 or equivalent (one-step colder for performance applications) × 8 — Motorcraft SP-534

Preparation

1. Ensure engine is completely cold to touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery terminal to prevent accidental starter engagement
4. Remove plastic engine cover by pulling upward on cover to release clips
5. Take photos of any wiring harness routing and connector positions for reference during reassembly

Procedure

1. 1

   Remove passenger side harness connectors
   Starting on the passenger side of the engine, disconnect all four ignition coil electrical connectors by pressing the tab and pulling straight up. Note the connector orientation for reinstallation.
2. 2

   Remove passenger side ignition coils
   Using a 7mm socket, remove the single bolt securing each ignition coil (four coils total on passenger side). Pull each coil straight up with a twisting motion to release from the spark plug. Set coils aside in order from front to back.
   Torque spec

   Ignition Coil Bolt14 Nm (10 lb-ft)
3. 3

   Clean passenger side spark plug wells
   Use compressed air or a vacuum to thoroughly clean debris from around each spark plug well. Any dirt or debris that falls into the cylinder can cause serious engine damage.
4. 4

   Remove passenger side spark plugs
   Using a 5/8" spark plug socket with extension, carefully remove each of the four spark plugs. Turn counterclockwise and ensure the socket seats fully on the plug hex. Inspect removed plugs for unusual wear patterns, which may indicate engine issues.
5. 5

   Remove driver side harness connectors
   Move to the driver side of the engine. Disconnect all four ignition coil electrical connectors using the same method as the passenger side. Take care not to damage the connector locking tabs.
6. 6

   Remove driver side ignition coils
   Remove the 7mm bolt from each of the four driver side ignition coils. Pull coils straight up with a twisting motion. The driver side may have less clearance than the passenger side due to brake master cylinder proximity.
   Torque spec

   Ignition Coil Bolt14 Nm (10 lb-ft)
7. 7

   Clean driver side spark plug wells
   Thoroughly clean all four driver side spark plug wells using compressed air or vacuum. Pay extra attention to ensure no debris remains that could fall into the cylinders.
8. 8

   Remove driver side spark plugs
   Remove all four driver side spark plugs using the 5/8" spark plug socket. Keep plugs in order if you plan to inspect them for diagnostic purposes. All eight cylinders should now have empty spark plug wells.
9. 9

   Prepare new spark plugs
   Verify the gap on all eight new spark plugs using a gap tool. Factory gap should be 0.052" to 0.056" (1.32-1.42mm) for stock applications. Apply a small amount of anti-seize compound to the threads of each spark plug, avoiding the electrode area. Do not over-apply as excess can contaminate the combustion chamber.
10. 10

    Install new spark plugs - passenger side
    Carefully thread each spark plug by hand into the passenger side cylinder head to ensure proper thread engagement. Once hand-tight, use the torque wrench to tighten to specification. Never use an impact tool on spark plugs in aluminum heads.
    Torque spec

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

    Install new spark plugs - driver side
    Repeat the installation process for the driver side, hand-threading each plug first, then torquing to specification. Ensure the torque wrench clicks for each plug to verify proper seating without over-tightening.
    Torque spec

    Spark Plug25 Nm (19 lb-ft)
12. 12

    Reinstall ignition coils - passenger side
    Apply a small amount of dielectric grease to the inside of each coil boot. Press each coil firmly onto its corresponding spark plug until it seats completely. Install and torque the 7mm retaining bolt for each coil.
    Torque spec

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

    Reinstall ignition coils - driver side
    Install all four driver side ignition coils in the same manner, ensuring each coil boot seats fully on the spark plug before securing with the retaining bolt. Torque all bolts to specification.
    Torque spec

    Ignition Coil Bolt14 Nm (10 lb-ft)
14. 14

    Reconnect electrical connectors
    Reconnect all eight ignition coil electrical connectors, ensuring each connector clicks into place securely. Verify the correct connector orientation based on photos taken during disassembly. Route any wiring harnesses to their original positions.
15. 15

    Reinstall engine cover and battery
    Align the plastic engine cover with the mounting clips and press down firmly until all clips engage. Reconnect the negative battery terminal.

Reassembly

1. Verify all eight ignition coil connectors are fully seated and locked
2. Ensure no tools or parts were left in the engine bay
3. Double-check that all ignition coil bolts are installed and torqued

Verification

• Start the engine and listen for smooth, even idle with no misfires or rough running
• Check for any flashing check engine light which would indicate a misfire condition
• Allow engine to reach operating temperature and verify smooth acceleration with no hesitation
• Use an OBD-II scanner to verify no misfire codes are present (P0300-P0308)
• Visually inspect for any spark plug wire or coil connector issues while engine is running

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