182 turbo diesel whistle?

[MDP91]

Bit of an odd one, been noticing that my 182 has a slight whistle when starting up or flooring it, sounds very similar to a turbo diesel! It doesn't tick or anything but just sounds abit turbo'ey! Any ideas what could be causing this, is it normal?

 

[syko6288]

Manifold to cat join leaking

 

[MDP91]

Yeah fitted a catback yesterday and we noticed it was knackered, I'm fitting a decat next month so it'll be all sorted.

 

[MDP91]

We couldn't feel it blowing at all though, and the sound doesn't seem like its coming from there.