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.
Rattlesnakes are usually identified by their warning rattle â a hiss or buzz â made by the rattles at the tip of their tails. A rattlesnake is born with a button, or rattler, and acquires a new rattle section each time it molts.