well, that's what I saw inside my IC just now...
I had it for a week or two but, today as I was modifying the endtank, I noticed a black dust, like an exhaust gas has passed thru it...all over on the inside

is it normal ? I mean IC in only cooling air from compressor to TB, so it shouldn't have any black smoke/dust in it ?

is it normal ? I am going to have to check for leakage but any advice or ideas before hand would help....btw, it is used.

 

The likely explanation is that small amounts of oil are blowing through from the turbo center housing into the compressor side, where they're blown out and deposited in the IC. If it's substantial, you may be in need of a turbo rebuild to fix those oil seals.

 

Its oil. When my turbo failed, there was oil in my intercooler piping.