This whole Piston Slap issue has turned into kind of a support group for dis-satisfied ford owners. I own a 1997 f150 5.4 that
after only 16,000 miles started to wrap. The dealer at this point couldn't detect a noise because it wasn't constant. So I returned two more times before the warranty ran out at 36,000 miles and at that time they told me what it was (piston slap) and it had no effect on the life of the motor. Well, (knock on wood) I'm still on the road at 130,000 miles and the truck wraps loud as ever when cold. (do you know how cold it gets in Minnesota in the winter?)

The truck has as much power as it ever did and doesn't show signs of letting up. It'll still pull our 27' Fifth Wheel Camper (7300lbs or so). Maybe Ford was correct on this engine life thing. If anyone has more miles can I hear from you and let me know what to expect.

By the way, I've looked into replacing the engine recently
just because I'd like to be ready for it when it comes, I could replace 3 of my old 351's for the price that it cost for one 5.4L
Hope it last a while.