Here's another example - when the car's warmed up, this is only when it happens. When I accellerate slowly, it starts to grind/rattle, but when I "get on it", the noise goes away, and when i slow down (mind you, my foot is still applying pressure to the gas pedal), the noise will return.
It's not loud, but significant enough to drive you NUTS!
The same thing was happening to my car, then 2 months later my engine blew.... have it looked at. It only gets worse after time. But to be sure its the same thing i would have to hear it myself