I got my motor all together (re-used tbelt tensioner)... after 500 miles now the timing belt slaps around at idle making a noisy ticking sound (def tbelt, not valves), it has loosened up a little bit. The timing belt I used was off my old motor with ~10k miles.

How did it loosen by itself, is it just as simple as that and I just need to retension it again or is this a sign of a timing belt tensioner going bad? It doesnt squeal at all... Im just trying to figure out the weak link before I start working on it. I am hoping I can just retension it and it will be fine...

 

try loosening it all the way and retightening it again, and if it gets loose again, assuming you know what youre doing, which im assuming you do, then id get a new one, they say to replace those with the timing belt i thought, i didnt the last time i changed a belt, and now that i think about it, it was still a little loose