Purchase 2004 F-150 Larriat Supercab. Noticed a slight "knocking" upon purchase, my inquiry was dismissed. Returned later to the service department to ask a technician to look into "knocking", again was dismissed. Prior to my warranty expiring I again returned to the dealership (Morries Ford - Minnetonka, Minnesota) and again was dismissed. The knocking grew worse and stopped in at a non-ford affiliated mechanic and within minutes was told of a TSB that had been out on the problem since prior to my purchase. In looking future - improper factory installed timing chain into the problem the mechanic discovered a timing chain to loose that he could stick his hand between it and the engine block, indicating that the chain was improperly installed at the factory as the timing chain will not stretch to cause this much slack, it will break first. In fact, the timing chain was so loose it had almost worn multiple holes in the timing cover. I took picture and kept the parts and contacted the dealership and Ford Corporate and they have continue to dismiss my claims. I have pictures, a TSB and mechanics that will swear to the items. I have continued to contact both the dealership and corporate, however it appears that my requests continue to fall on deaf ears.