I have a wonderful 82 300TD named Blu. Engine runs great, however when excelerating at highway speed, or going up hills, I get this whinning squaling sound that sounds like the turbo kicking in. It really sounds like a belt squealing.
I know there has to be another thread of this but if you search on 'Turbo' seems to be a highly used word, and 'turbo noise' got me a thread where it was the air tube, but their description of their noise seems different than mine. I also don't know what the turbo looks like exactly.
I will point out that the rubber mounts the air filter sits on are shot, and I get blow by in the air filter.
Expect that very little has been maintained as far as turbo hoses. Should that be the first place I look?