Puma ST noise on acceleration

[HRF1T2020]

Hi

My Puma ST now on 10k 10 months old, think has always made this noise I think 🤔

So always warm as never push when cold, on acceleration upper medium to hard there's a noise heard with window down that's from engine bay

It sounds like a rattle you get from a diesel but much quieter/Tappet(best can describe it really) , only on hard acceleration

Wondering if it's the wastegate or fuel rail or just injectors, or just the sound of the 3pot 1.5engine
It's in for its first service in July all fluid/oil levels are fine and response etc is excellent mpg not bad for ST 42mpg

Doesnt do it on normal acceleration, revved when parked 

Thanks