While cleaning my engine today I took a close look at the spot of soot that's been re-appearing on my turbo and heat shield since I bought my car last year, and noticed what looked like two very tiny holes. Thinking I must be crazy, I did a quick search in this forum and found other 85 California turbos with holes in them. Double checked my car, and sure enough, a tiny amount of air was coming through the holes. Looks like a few bad castings on that particular model. I was not looking forward to buying a new turbo, and since it didn't seem to be affecting the performance, I was hoping for a cheap fix.

Went to the trusty Autozone down the street and found something called "Thermosteel" http://www.ksealit.com/thermosteel-4-p.asp . After I got home I took a wire brush and dental pick to the holes, and sprayed them out with brake cleaner. Packed the now slightly larger holes with the thermosteel paste, and wiped off the excess.

It probably dried out too fast from the residual heat in the turbo, but I think it may do the trick. A very quick test run showed no leaks, and I can't say for sure where the holes were before I filled them. The paste is supposed to be good up to 2400ºF, and its dense as hell. We'll see if it holds.