is the sound coming from the engine bay, or from the steering column?
mine did something that seems like it might be similar to what you are describing ... it was coming from the steering column. the wheel would sometimes be hard to turn ... it felt like there was a bearing in the column that had gotten sticky and was getting ground down or something. eventually it was no longer hard to turn, but it had gotten loose. i didn't feel like dealing with trying to take it apart to see what the problem was, so i decided to get a new steering column.
*edit* lol re-reading your response, it doesn't sound like my situation any more, so never mind