[Sindri]

I have a brand new 2021 1SS 1LE that I picked up Nov. 30th and I'm already having an issue. I've been driving the car every day since I got it, and am doing my best to follow the GM break in procedures - not dogging it or thrashing, varying RPM, keeping it under 4,000, etc. I mostly drive it in Sport mode, but have used it in Touring a few times. I feel like I've got a pretty good handle on how the car feels and the noises it should be making.

Well last night I was turning into my neighborhood and I heard a very sharp, distinct noise, like a sudden bang/pop, and then the car was louder. The only way I can describe it is like a hole suddenly appeared in my firewall and I was hearing more wind/road/engine noise coming from that area.

Today I took a look under the hood, my first thought was the sound tube became damaged/disconnected, but it seemed fine. I also looked under the car for anything that was damaged/dragging but didn't see anything.

I took it out for another drive today, and the noise is still there, and seems like it's getting worse. I usually run in Sport but switched to Touring and it's even more apparent. I've also noticed that there's some more vibration in the clutch/shifter and in the bottom of my seat. I also am detecting a sort of clicking/grinding noise that seems to be proportional to engine RPM. I'm familiar with clutch chatter in multi-plate setups but this seems somehow different/worse.

My first thought is something transmission related owing to the vibration in the shifter/clutch area. The other thing I'm thinking is something exhaust related, maybe a leak up near the header or cat? It's obviously still under warranty, so I'll end up taking it to the dealer and letting them address it, but I always like to do my homework before turning my car over to someone.

I'm just curious if anyone has experienced something like this. I find it helpful to be able to show up to the dealer with a list of symptoms and possible explanations.