It seems to me the metal gaskets in the turbo and manifold do their sealing in two ways:
1) the pinch seam on the inside edge gets squashed
2) there is a ripple that runs around the middle of the gasket flange and gets squashed.

Both of these concepts support the use one, throw away theory on exhaust gaskets.

When I took apart my turbos this fall I noticed some gasket blowby in small spots (precontrol hatch cover, etc). Note there is no OEM part replacement for this gasket.

I thought I had found the source of my leak last time (a non-tensioning dp stud) but it didn't fix it. I may pull the turbos again soon to try fixing the gaskets and looking closer still. New turbos are a lovely answer that I can't budget. Maybe next year.

Is there a suitable metal foil that might be used in addition to the used gasket?

I might try reforming the ripple by gently tapping the gasket over some solid core wire or something, and then lightly cleaning it with emory cloth. Does this kind of thing work?

Any other tricks to ensure a good seal?

Dave

 

You need to make sure the flange surfaces are VERY clean and flat. Carbon build-up and the like can cause a small exhaust leak.

Dale

 

That's why I figured the emory cloth would be the best choice. Maybe I should use a wet sand series down to 1000 grit. I know last time the gaskets were NOT cleaned.

Do you also sand/finish the mating surfaces of the pipes and manifolds? (I'm getting desperate to put a stop to the leak)

Dave