update: so my gauge reads about -18 or -19 hg vac which seems normal.

I did a bit of looking into the engine when the needle on the gauge rises every 10 seconds.

It seems every 6 seconds to be exact a surge noise comes from around the boost bypass valve. Is this normal? It happens on the same time interval each time 6 secs exactly. This is with ac completely off.

When i turn ac on it stays steady at -18 to -19 vac no surge noise no fluctuation on the gauge

any thoughts??