Hmmm...just wondering....if a head gasket blows on the outside (no coolant getting into combustion chamber but exhaust gases escaping from cylinder heads) would that technically be considered an exhaust leak? And possibly be audible? (hissing/sound of plastic bag in the wind). Just curious. I remember last I went to check my P/S fluid the cap was covered in soot.... and I also feel like at the base of the sc body looks like there might be some too for some reason, all around the perimeter of it.