I have an 04 F150 and i also hear a tick, It is lounder at low idle and its soft enough that i'm usually the only one who hears it but that being said it still bothered me. If it is the same sound everone is talking about, the rumor i heard is that when the motor was redesigned the surfaces on the engine and the exhaust manifold remained the same however the exhaust manifold gasket was made thinner on the inside portion. By inside portion i mean closer to the exhaust channels in the manifold. since a very minute space exist there, after some wear the gasket begins to flutter against the exhaust manifold making a small tapping sound and once the engine revs up the gasket is press outward agaist it causing the sound to fade away. i asked if the problem ever gets worse or is something i should fix and the replacement of the gasket is a job on the books slated for about 9 hours. I think that comes to more than i should pay for peace of mind. let me know if that helps at all or if it sounds like i've been bamboozled.