How to Replace Spark Plugs in a Ford F-Series

The Ford F-Series is a family of trucks that ranges in size and hauling capacity. The F-Series includes the F-150, F-250, F-350, F-450 and the F-550. Ford suggests you replace spark plugs on the F-Series trucks every 30,000 to 60,000 miles, depending on the wear on the vehicle.

Instructions

1

Park the truck in a shady area and allow the engine to cool completely.

2

Access the spark plugs. For a 4.6 L, 5.4 L or 6.8 L F-Series engine, disconnect the negative battery cable first and then remove the ignition coil electrical connector. On all other engine sizes, the spark plug wires are located along the sides of the engine.

3

Grab the spark plug wire boot and turn it to the right and then to the left. Pull back on the wire to remove it from the spark plug. Complete the process of replacing each spark plug before starting on the next one to avoid damaging the engine.

4

Connect the socket and the old spark plug. Loosen the spark plug and remove it from the F-Series engine.

5

Brush out the cylinder well and wire boot gently. Apply anti-seize to the inside of the wire boot and around the threads of the spark plug.

6

Screw the new spark plug into the cylinder well and secure it tightly in place. Test the tension of the spark plug. The measurement needs to match the required tension, which is listed on the spark plug's package.

7

Repeat Steps 3 through 6 for the remaining spark plugs. When you finish replacing all of the spark plugs, replace anything that was taken out to gain access to the plugs in Step 2.