Possible Clues:

• Rod goes round after nut case? The mechanic will know what this is!
• Rotating engine part
• Rotating part of engine driving the pistons
• College is nasty to staff - it drives one of those looking for a move
• Nuts start to hold back part of engine
• Nut on beam in engine part
• Model T feature
• The odd person’s hat, smothering loud part of engine
• Nut to rip off part of the engine
• Nuts attached to bonnet maybe limiting force in part of engine