Rattling on acceleration

[Ashesofthewake]

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.

[EvoEatr]

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.

Could be a loose heatshield or something ( I know hard to believe at that mileage). However I did have a 2010 outback the other day with an ungodly noise which turned out to be a shield got bent a tad and was rubbing on the driveshaft. Its under warranty...

[Anub1s]

Your car is still under warranty, take it in to the dealership and tell them to fix that ****.