...heated up. ? My 2001 Chrysler 300M makes this sound when i accelerate only when the car has been heated. i hear no sound when the car is cold. i only hear it when the car starts to warm and and it continues. you can hardly hear the sound but the sound is there. i took it back where i bought it and they said its nothing wrong. could it be the oil? they said just to drive the car. i do have extended power-train warranty though. so im not really worrying about it. any feedback on this?