Here is an interesting thought, does it go away when you turn your A/C on?

My old car developed a really nasty high-pitched squeal, but when I would turn the A/C on it would go away. Took it to a mechanic and they adjusted the A/C compressor clutch and that took care of it. $40.

 

could be the clutchon the AC compressor...I know mine started to make a scratching/ bad bearing noise.....and originally thought it was the alternator til I did some diagnosing.

 

Just today I was driving down the road and heard a sound similar to when you're breaks are wearing down coming from my car. I was in 5th doing about 45 and would hear it for a second, then it'd go away, then come back and fade away. It didn't have a definite pattern and for some reason would only do it while I was in 5th between 1500 to 2000 RPM. The weird thing is I took my dad for a drive so he could listen to it and it of course didn't make a sound then. On top of that, the original noise that I described, the whining sound that we now believe was a vacuum leak, was nearly non-existant. Frankly, I don't know what the hell is going on, the car is running strong as hell, clutch and transmission feel solid. Looks like I'm just going to have to play the waiting game and see if I hear it some more or if any other tell tale signs show up.