Not an erratic idle like a dirty throttle body gives you. That goes up and down when the AC compressor kicks on, and can send the idle down to 300-400 RPM and stall the engine out. Then it overshoots when the compressor cycles off.
death rattle. a sound produced by a person immediately preceding death, resulting from the passage of air through the mucus in the throat.
To rattle is to make a series of sharp sounds, such as metal clacking on a chain. 1  An example of rattle is when dishes clatter on a tray and make sharp sounds. An example of a rattle is the sound made as dishes are unloaded from a dishwasher. 2  An example of a rattle is a child's toy that is filled with beads that clatter when the toy is shaken.