Our new 320S whistles when your floor it, the 2016 one didn’t. But I wouldn’t call it a horrible noise, neither would I call it a fault? Nobody here has ever commented on it anyway. It’s quite discrete- Doesn’t really matter does it?
That’s the point though. The older models never made any turbo noise.
Anyway I find it annoying as it runs pretty much all day ... the only useful thing is that I know where the machine is around the farm