This my old bolt which i changed before i had the chains done, when you press it in it should spring back smoothly. My old one use to get stuck some times when coming back out. This at it's normal postion. [lightbox=../../e107_files/public/1175756771_611_FT168064_000_0006.jpg][/lightbox] and this where it used to get stuck. [lightbox=../../e107_files/public/1175756830_611_FT168064_000_0005.jpg][/lightbox] But this is what OBD2 bolt looks like on a 1997 VR6 Highline. Are you sure it's chain rattle as at 3000rpm it should go away, the rattle should be around 1200rpm mark