yesterday, the loco Superintendent picked up a new 45xx (GWR small prairie). It looks lovely. But on running it has a noticeable growl that actually cycles with the driving wheel rotation. The growl disappears going down a grade and is more noticeable in a climb. We did the 30 minutes, unloaded, each way at moderate speed "run in" (like Bachmann suggest) but this did not ease the problem.
We got a Bachmann 64xx a few months back and it runs silent. The first loco on the layout, a Hornby 49xx, runs beautifully silent.
We also have an old 14xx that we picked up 2nd hand. This sounds like a 2 year old shaking a box of marbles. But we're cutting it some slack as it's decades old.
So my question is, How quiet should you expect a new loco to be?