The glow plugs on your Ford engine are designed to preheat the engine in diesel systems, allowing the motor to start easier, especially in cold weather climates. These glow plugs eventually wear out over time due to extreme conditions or use and need to be replaced. Changing the glow plugs is a fairly easy thing to do and you can do it yourself in about three or four hours, saving you the expense of having it done in a shop.
Detach the valve cover of your Ford truck using a socket wrench to remove the bolts, holding the cover in place.
Lift the cover away from the engine carefully, sliding it out and setting it aside.
Disconnect the electrical connectors on top of the glow plugs by using a pair of pliers.
Loosen the glow plugs out of the engine with a socket wrench; then pull them out.
Replace the glow plugs with new plugs and secure with a socket wrench; then reattach each of the electrical connectors.
Clean the old gasket material off the valve cover and replace with a new gasket; then slide the valve cover gasket back into place on the engine.
Secure the valve cover by using a socket wrench to tighten the bolts down on the cover.
Repeat Steps 1 through 7 for the opposite side of the engine.
Since you have to take the valve covers off to get to the glow plugs, replace the valve cover gaskets as well.
Always allow the Ford engine to cool down before attempting to replace the glow plugs in the engine.