I mentioned this earlier about my car but it seems not right. I've been doing a lot of uphill driving lately on my new coupe - Only 280 miles on it - and when I'm going up an incline that's pretty steep, I keep in first and the RPM's get up to about 3100 or so at about 20 MPH.

Then, once the street flatens out, I shift down to 2nd... but once I do that, even thought I'm in a flat surface and going probably 25 mph or so, I hear a faint rattle or clanking noise. Sounds like when something loose is flinging around in a barrel something. (Just clanking inside, if that makes any sense)

Then, once I got to my destination, there is a slight burning smell, but I think that's due to the car being new still... I think.

Anyhow, I also noticed when I shift to 2nd and I quickly accelerate... I get the same noise. Not loud, faint but still annoying.

Any insight esteemed peoples of this site?

 

can you determine if you hear this inside the car, from the cabin? Or can you hear it coming from the outside if you roll your windows down? It's better to isolate from where the noise is coming from, inside or outside.

 

It's definitely from the outside... and I can hear it louder when I roll down the window.

 

Could it be the rear axle rattle?