Hey guys, I have a question that I cannot find the answer to. I have a '91 5.0 LX and when I start the car it starts up fine, but a second or two after startup I'll hear this loud rolling/rattling/clanking sound for a second then it goes away and the car is fine. As I'm driving, I hear nothing out of the ordinary, but when I'm at a stoplight idling for a little bit, I start to hear the same noise from startup, only now it keeps going and going the whole time I'm idling, and the second I touch the gas to go, the noise stops. I'm not sure but it sounds like it's coming from under the car, like the transmission or driveshaft, and I do have a 5-speed. To me, that's where it sounds like it's coming from, sometimes I can feel the vibration from the rolling/rattling/clanking under the floorboard. Also, whatever it is, it sounds like it's spinning or rolling, and it sounds kind of heavy too. Any info would help because I have no clue where to start diagnosing. Thanks.