I just noticed this today. vaping away and it seems like an air bubble popped inside the atty and warm air rushes into your mouth. Anyone every experience this? Weird. Atty death quiver? It's not a gentle puff of air but a sensation that a bubble popped in the atty. Would/Could saliva cause this? 
Mini, de-bridged joye lr510.

Mini, de-bridged joye lr510.