Okay so my gasket from my turbo to downpipe has been on the fritz, and I think I finally got rid of any seal there may have been, so I have a huge exhaust leak after the turbo. However I noticed on my drive home the other day, that I was progressively loosing boost..basically I'm at 1.5psi now, I could hear my turbo spooling, I parked it for now, compresser wheel seems in good shape, I'm thinking it may be my wastegate..any suggestions??? Also does anyone know what size hose O.D. or I.D. I should be using on the wastegate port (to turbo I guess) Does size matter that much??? Or do you generally just want it to be tight on the nipple (If you call it that)? Thanks for any help...

 

if you can hear the turbocharger building boost it probably isn't the wastegate. you may have a boost leak somewhere in your charge pipes...

 

You could have a boost/vac leak in the intake or possibly an exhaust leak before the turbo (block to manifold or manifold to turbo).

 

or you could have a leak in the line going to your boost gauge.

 

Well I went to the local hardware store, picked up some stuff and built a boost leak tester, definitely leaking somewhere, couldn't get it to build pressure I can hear it escaping somewhere on the right side of the turbo( side facing block), guess I won't be able to tell till I pull my turbo off this weekend, hard to say, just glad I have an extra turbo.

 

Sounds like your UIM or LIM might have a compromised mating seal and not the turbo itself leaking. Also, what you heard could be the air escaping through the exhaust, which is normal. The seals aren't 100% air tight. But you did say you couldn't get it to build pressure, so I'm thinking UIM or LIM gasket not sealing. Maybe you have loose bolts or maybe one of the gaskets gave way.

 

Gaskets are cheap. Even factory ones. I'd grab a factory Mazda exhaust gasket and call it done!