rattling sound from 2000-3000 rpm

[madugo]

so i have been noticed a few times that when gear shifting from 2-3 and 3-4, and during 2000-3000 rpm, either the engine or the exhaust had some rattling/higher pitch engine sound.
but if i switch it to sports shift and try to go a little harder on the gas, it does not make the sound, i think maybe because it past 2000-3000rpm faster than normal driving?
anyone experience this or know why it does that? the car is 14 model and has less than 900 miles.


thanks.

 

[CX_CO]

To clarify what my issue was, there was high pitched rattling sound (like shaking loose change in a coffee can?) only during acceleration and between 2k-3k rpm. Thought it was a loose firewall for a while but the dealer took them all out and the noise was still there.

Spent a month at the dealer with a Mazda tech from Japan and they couldn't figure this out. I finally just adjusted the rubber bump stops under the hood to give it less play and the sound went away. Still don't know what the problem was, but I'm assuming it was something in the engine bay. Hope this helps though.