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.
This may happen during the last few hours or even the last few days of your life. As death approaches, your breathing may become moist and congested. This has been called the death rattle.. Breathing changes commonly develop when you are weak and normal secretions in your airways and lungs become trapped.