I got a small clanking noise well maybe not as loud as a clank but a small tick untill the truck warms up but after that its fine, could it be the pistons just not warm, I have no performance problems or anything else but what worries me a little bit is that i had the noise a few months ago and i had a problem with my T-Stat and i replaced it and the noise was gone after this. And i only say that b/c when i replaced the T-Stat the metal was broken apart which i have never seen before so i dont know if something is causing this or what it could be.

thanx
Jay

Even if a part from the thermostat came loose, it would be in the cooling lines, not the engine. The clanking your hearing might be noise from the timing chain. Search this site, there's a wealth of information on it. It was even covered by a recall. You can also have valve noise when you first start the engine due to lack of oil. A different filter may help.