Had the car a couple of weeks now and last night it started to blow around the manifold area and turbo was struggling to spool properly, upon looking this morning the manifold to turbo nuts are loose is there any good nuts to use to replace them? A mate suggested copper ones but can you get them and what size are they?

Also the car has a switch labeled "boost" it normally runs 12psi but when you flick this it goes up to 19 and when on full boost it makes a scratchy hissing kind of noise but only when this switch is on could it be a boost leak from the loose nuts?

Thanks

 

Replace the nuts go to b&q and you will find some better bolts

Sort the leak out first