My 09 sedan has about 6k on the clock now, and today on my way home from class i pushed it a little bit (up to about 4.5k, nothing extreme) coming out of a turn. While I was accelerating I heard a rattling sound that sounded a bit like someone tossing a nut into a coffee can and shaking it. It was over as quick as it started when I let off the accelerator.
My first thought was here comes my spun bearing! (08/08 manufacture) but I did a relatively quick acceleration bringing it up to about 4.5/5k at the next two stop lights and didn't hear a peep. I listened to the idle when I got home and it sounds normal.
I don't beat on this car at all, I keep the miles low and drive like a grandma with the occasional hard acceleration conditions permitting.
Any ideas what could be causing that? I'm stumped.
Edit: Car is bone stock.