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.
rattlesnake - Children's Encyclopedia (Ages 8-11) Rattlesnakes are poisonous snakes that have rattles in their tails. A rattlesnake shakes its rattle to threaten, or warn off, other animals. A rattlesnake is a type of poisonous snake that shakes a rattle on the end of its tail to warn off other animals.