Ive got 2006 GT thats been sitting for a couple years.Just recently had the 5R55S automatic tranny rebuilt.Ive noticed a rattling noise coming from somewhere under the hood I think but honestly cant pinpoint it.Ive checked the exhaust,the bellhousing bolts,flywheel cover,etc.Everything seems to be tight and where it should be.Im kind of leaning towards it maybe being an issue with the timing chains and/or guides.Im not sure what that would sound like.I tried to post a video of the rattle noise but it wouldnt let me.theres a link to the video below.Any help would be much appreciated.
https://imgur.com/a/D2TcmSy
https://imgur.com/a/D2TcmSy