Fitted an sti tmic as in previous thread and all was fine. Now today developed a boost leak (sounds like dentist drill). I removed cooler and checked all hoses tight and put back on. Its quieter but still there. Its got an aftermarket d.v on it that has been on since ive had car. Could it be this or the gasket? Its not a forge item it looks like a collins performance valve. Ive taken it off cleaned and put back on and still got the noise

 

Gasket behind the DV is quite commong for going and causing a leak, as far as I'm aware.

 

get it smoke tested problem solved no more guess work

 

Mine turned out to be that gasket too

 

Didn't show up when I had it smoke tested before tho. I tried loads a stuff n then i tried a bit of blue sealant on the dump valve gasket and no more leak

 

Ill try new gasket today. Thanks

 

Brought some of that blue instant gasket today and problem solved. Many thanks for help