Spark Plugs - V6

Replace all eight spark plugs on the 5.0L V8 Coyote engine, including removal of ignition coils and necessary access components.

Warnings

Tools required

Parts

• Spark plugs (Ford Motorcraft SP-546 or equivalent) × 8 — Motorcraft SP-546

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely for at least 2 hours if recently driven
3. Disconnect negative battery terminal using 10mm socket
4. Verify you have the correct spark plugs for the 5.0L Coyote engine (Motorcraft SP-546 or equivalent)
5. Inspect new spark plugs for shipping damage before installation
6. Clean engine bay around ignition coil area to prevent debris from entering cylinders

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly and pull upward to disengage the retention clips. The cover is held by push clips only and does not require tool removal. Set cover aside in a clean area.
2. 2

   Disconnect ignition coil connectors
   Locate all eight ignition coils on top of the engine (four per cylinder bank). Press the locking tab on each coil electrical connector and pull straight up to disconnect. Mark or photograph connector locations if needed for reference during reassembly.
3. 3

   Remove ignition coils - driver side bank
   Using an 8mm socket, remove the single bolt securing each of the four ignition coils on the driver side cylinder bank. Pull each coil straight up with a slight twisting motion to remove from spark plug well. Inspect coil boots for damage or oil contamination.
   ⚠If coil boots are oil-soaked, valve cover gaskets may be leaking. Address oil leaks before installing new spark plugs to prevent future fouling.
   Torque spec

   Ignition Coil Bolt14 Nm (10 lb-ft)
4. 4

   Remove ignition coils - passenger side bank
   Repeat ignition coil removal process for the four coils on the passenger side cylinder bank. Remove the 8mm bolt from each coil and pull coils straight up from spark plug wells. Keep coils organized by cylinder location if they will be reused.
   Torque spec

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

   Clean spark plug wells
   Use compressed air or shop vacuum to remove any debris, dirt, or oil from each spark plug well before removing plugs. Debris falling into cylinders can cause engine damage. Ensure wells are completely clean and dry.
   ⚠️Never allow foreign material to fall into open spark plug holes. Even small debris can cause catastrophic engine damage when engine is started.
6. 6

   Remove old spark plugs
   Using a 5/8-inch spark plug socket with extension, carefully loosen each spark plug 1-2 turns. If significant resistance is felt, stop and apply penetrating oil, then wait 15 minutes. Once loosened, unscrew plugs completely by hand to prevent cross-threading. Remove all eight plugs and inspect for abnormal wear, oil fouling, or electrode damage that may indicate engine issues.
7. 7

   Gap and prepare new spark plugs
   Using a spark plug gap tool, verify each new plug is gapped to Ford specification (typically 0.050-0.054 inches for this engine, verify with plug manufacturer). Apply a small amount of anti-seize compound to the threads of each plug, avoiding the electrode area. Do not over-apply anti-seize as excess can foul the plug.
   ℹ️Anti-seize is required for aluminum cylinder heads to prevent thread galling and allow future removal without damage.
8. 8

   Install new spark plugs
   Carefully thread each new spark plug by hand into its cylinder. Turn clockwise until finger-tight, ensuring plugs thread smoothly without resistance. If resistance is felt, back out and restart - do not force. Once all plugs are hand-tight, use torque wrench and 5/8-inch spark plug socket to tighten to specification. Tighten plugs in a cross-pattern (alternating between banks) to ensure even seating.
   ⚠Must use torque wrench. Over-torquing will strip aluminum threads; under-torquing can cause combustion leaks and plug blowout.
   Torque spec

   Spark Plug25 Nm (19 lb-ft)
9. 9

   Reinstall ignition coils
   Apply a thin layer of dielectric grease to the inside of each ignition coil boot. Insert each coil into its spark plug well, ensuring the boot fully seats on the spark plug terminal. Install the 8mm retaining bolt for each coil and tighten to specification. Verify coils are fully seated and not standing proud of the valve cover surface.
   Torque spec

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

    Reconnect electrical connectors
    Reconnect the electrical connector to each ignition coil, ensuring the locking tab clicks into place. Gently tug on each connector to verify secure connection. Double-check that all eight coils are connected.
11. 11

    Reinstall engine cover and battery
    Align engine cover with mounting clips and press firmly until all clips engage with an audible click. Reconnect negative battery terminal and tighten securely with 10mm socket.

Reassembly

1. Ensure all eight ignition coil electrical connectors are fully seated and locked
2. Verify engine cover is properly clipped into place on all mounting points
3. Confirm no tools or parts have been left in engine bay

Verification

• Start engine and listen for smooth idle with no misfires or rough running
• Check for any signs of arcing or spark leakage around ignition coils in low-light conditions
• Verify no check engine light illuminates and no misfire codes are stored
• Test drive vehicle under light acceleration to confirm smooth operation across all RPM ranges
• Monitor fuel economy over next few tanks - properly gapped new plugs should improve efficiency if old plugs were worn

More procedures for this vehicle