The rattle might come from the inability of the head to seek to track zero and it just keeps trying. I engineered hard drives but it was in 1980's. At any rate if it rattles and it does not work just replace it. There is not much chance to get the data out however. An IT guy told me recently that if a drive is just starting to go, showing signs of not working but still working until it warms up, he would put it in the refrigerator for a few hours then plug it in to the compuiter and get the files he wanted from it as fast as he could.

