2011 fiat punto evo, when accelerating quickly in 1st and 2nd gear there seams to be a rattling/grindry noise between 1.5k-3ishK revs , sounds like an external beam rattling or something but nothing seams to be loose.
Can anyone help out seen a few threads but not many solutions?
Any help appreciated cheers.

Check that the air intake tube which connects to the air filter box on the left side hasn't become loose from the holder. The tube has a rubber damper. Push it in. It's a very common source of noise.

I second eeeno's response. I had exactly the same problem in my Grande Punto on a couple of occasions, specifically after servicing, as the rubber damper in my case was damaged, preventing it from being correctly pushed back in. It produces an exhaust like rattle in the 2,500-3,000rpm range, 1st and 2nd gear.

Literally the most minor problem imaginable

Luckily usually it's just this smaller issue, but of course Fire engines usually develop leaky exhaust gasket due to broken bolts on the manifold. That costs a lot more to fix.

I didn't know that about the exhaust gaskets. I'll keep that in mind in case it happens to me!