Hi guys hope you're all well?
Just wondered if anyone could shed some light on a strange hissing noise I have Even under gentle acceleration that sounds to be coming from deep within the right hand side of my dashboard before I strip it all out looking blind. My car has cruise control and I'm aware that there are vacuum connectors behind there however the boost gauge and cruise control both function fine so I was wondering if it could be anything else? It is quite noticeable and has done it for months! Can the turbo cbv leak or would that cause running problems as it runs great.

In the engine bay all of my hoses are new and tightened and vacuum hoses are fine Other than the large one to the brake master which looks to be ok and so Iv Never fiddled with it

Thanks!