Yes, probably gunky juice. There was a problem a while back with some of the PT coils in that the wire would burn a rubber gasket. It was pretty awful but at least you could tell--painfully obvious--you were vaping burnt rubber rubber and change the coil.Most acrid air I have ever breathed was in Paris, France. Nose and throat would burn for the first 15 minutes or so when we started out for the day. This was back in 1994. I don't think they hade any emission control on vehicles. The busses were the worst! Love that city though. Would love to go back.
Anyway, I did a coil change and noted the tiny holes on the sides were blackened. I would guess that would be gunked up. The little holes in sides of the coils that are still in the package are white (at least what's inside them looks white).
Gas mask on your next trip.