For the past month, i have been hearing a squeaking noise at about 1800 rpm. It sounds like a bad bearing or something. If i go below or above that it doesn't do it. It doesn't matter if it's hot or cold out side or if the engine is hot or cold. It will also do it at 2800 rpm once in a while. It doesn't do it when the car is in netral or park either. I can't seem to find where the sound is coming from. Any ideas?