I understand it's supposed to be a sporadic crack from the fuel etc. but it sounds a lot worse when multiple instances of the sample are overlaid (e.g. working in/near furnace columns).
Ideally(?) it'd be an extra sound layered on top of the base loop with some further randomisation between close sources using the same effect to make it sound more "natural".
The environment sound of different entities should be played with some offset relative to each other to produce sufficiently unique noise.
I'm still sure this is not a bug or an audiofile flaw, are you sure it was introduced in 0.15?