i have a weird problem...it was at the dealer for 3 days and they say they cant figure it out.

anyway, when i let my car sit over night and go to start it, there is a loud rattle/grinding noise comming from under the truck....

they said the starter is fine.

it only happens when the truck sits for a while..

any ideas?

 

Adjust the heat shields that are vibrating on the frame. It's after the cats at the cross member.

 

What kind of oil filter are you using?

 

I would think either heat shield or possible exhaust rattle....I had a meteal piece (baffle) break off inside my old Flow 40s in the stang and it would rattle at idle from time to time...annoying..finally cut the pipe off and dumped it out then re-attached.