With my windows down and the vehicle up to full temp, I notice a high pitched squeel. Almost like a brake warning tab.....but it isn't.

It only appears on off-idle throttle, and in mid-range, then goes away after heavier throttle, or letting off all together.

I've checked vacuum lines, and listened to accessories till I'm almost intimate with the parts.

I've tightened all the intake tube clamps, airbox clamps, and checked every vacuum line possible for leake, mis-fitting or a possible leak. No "Check Engine" lights as well...........so it can't be that bad of a leak. (assuming it's a leak.)

I'm beginning to suspect an alternator bearing....... Off idle....mild load.........(???)

Anyone else experience this?