J30 Noise

[Naison]

Hey guys,looking for some clues here. My J30 makes a grinding..ish noise when in Park or neutral but as soon as I put it in any gear it goes away. The car drives just fine.
It only makes the noise when it is in Park or Neutral. For example when I get in and start the car, the noise is there. As soon as I put the car in reverse or Drive the noise goes away.Sometimes if I shut off the engine and restart it the sound may also disappear.

Any ideas???

[driverdriver]

Does the noise occur only at start or is there all the time?

[Naison]

No it's not all the time.Just once in awhile. If I drive for awhile and then go to park when I put it in park it may start to make the noise and it would disappear if I restart the car.