above is a video what the noise exactly sounds like Okay so for the past week I would say I've been having this extremely loud rattling under the hood of my car. I took it to my friends work they told me sounds like the flywheel. When I had a friend of mine which is mechanic listen to a video of he noise he told me ac pulley of ac compressor or loose heat sheild, when my dad checked he said same thing pulley of heat sheild. My car starts up great and doesn't shift rough at all. It's just this extremely loud rattling noise that I can't figure out where it's coming from or what it could be. It makes the noise when I start the car at idle and when I drive... Someone please help me because this is making me not sleep haha.