A screw loose

something out of order, so that work is not done smoothly; as, there is a screw loose somewhere.

See also: Screw

References in periodicals archive ?
Ali Rowatt admits she's got a screw loose as she starts final preparations for the world's toughest triathlon.
IT has been said many times that I have a screw loose.
So you haven't got a screw loose if you think there is something a little curious about these images of Tower Bridge in London, Rome's Colosseum and Sanatorini in Greece, among others.
Germany doesn t have a screw loose, it has no less than 348 million screws loose.
"I truly believe he has a screw loose, a few screws loose actually," said Haye, who is coming out of retirement for the fight following his points defeat to Wladimir last July.
But when one of the 'bots is accused of tossing his maker out a window, it looks like Spooner might not have a screw loose after all, though there are a couple of machines trying to throw a wrench into his works.