We have a 2000 Expedition with a 4.6 liter V8. This has happened 3 times, 1 time before we bought the vehicle, when we hit a water puddle it will knock out a coil pack, not sure of the correct name for piece but it replaces the Coil and plug wire on the spark plug. I guess water gets in under the hood and gets the coil pack wet. Has anybody heard of a fix for this other than avoiding the water, which we try to do.

Hmmm...you shouldn't have to avoid water with it, that shouldn't happen at all!

If you have any warranty left on the vehicle, i'd suggest using it at a ford dealership as i have no idea what would cause that.

If you don't have any extended warranty on the vehicle, i'd recommend buying some and being patient for a month until you can make a claim. Then it will get taken care of if it continues in the future. Plus, if anything else weird happens you'll be covered.