I was reading some Elmore Leonard last night when something went ploink, like water dripping into a shallow pan in a kitchen sink. Only I don't have a sink.
About twenty seconds later, another ploink. What could be dripping? Gas? I don't smell it.
Coolant? Nah, not at the back of the van with the nose pointed slightly down.
Ah-ha! On the shelf next to me was a Coke Zero can I'd crushed a little as a reminder it's empty. Something about the way I'd crushed it, and the changing temperature, created tension that was trying to uncrush the can.
I stomped the can flat. No more ploinking. Back to my book.