How to Install Bosch Spark Plugs in a 1998 Ford F-150 5.4

The 5.4L eight-cylinder Ford F-150 engine comes stock with standard spark plugs. Upgrading to Bosch split platinum or quad platinum spark plugs will increase the gas mileage and performance of the vehicle. Installing spark plugs normally requires proper gapping; however, the Bosch lineup is pre-gapped, making installation even easier. The 5.4L uses individual coil packs on each spark plug. You should only remove and install one plug at a time to avoid mixing up the wires and connections.

• 1

  Disconnect the electrical connection to the spark plug. Squeeze the sides to disengage the locks then wiggle it free. Push the connection to the side.

• 2

  Remove the retaining screw from the coil pack with a Phillips head screwdriver. Set the screw to the side. Carefully pull the coil pack free of the spark plug.

• 3

  Blow out the spark plug hole with a can of compressed air.

• 4

  Remove the spark plug with a ratchet and spark plug attachment. Turn the ratchet counterclockwise slowly to remove the spark plug. Turn the plug clockwise briefly if the plug starts to become difficult to turn.

• 5

  Install the Bosch plug into its hole. Turn the plug clockwise. Back the plug out and reinstall it if it starts to seize up while turning. Rotate the plug until it is firmly seated. Do not over-tighten the plug; just minimal force is necessary to properly seat the plug.

• 6

  Reattach the coil by gently pushing it until it clicks into place. Reinstall the retaining screw and reconnect the wiring harness.

• 7

  Repeat Steps 1 through 6 for the remaining seven plugs.