can someone please help me out? my car makes this popcorn popping noise even when it’s parked. as you can hear, it’s intermittent. I have no idea what it could be. thanks everyone !
That is the sound made by heat shields as they heat up and cool down. You may have one that is either cracked or has a slightly loose bolt. They are located around the exhaust manifold and catalytic converters.
Another place to look is at the exhaust manifold(s) especially if they are cast metal. GM has had some issues with cracking on those, typically in or around the valleys between tubes.