Worn Speedometer Cable?
 

what are the symptoms of a speedo cable that is on its way out? I think thats what is happening....lots of buzzing/intermittent when driving, gets worse when using accelerator, usually stops when stopped or slowing down. My old cavalier had same thing and I was told it was a speedometer cable. No issues with actual meter though.

What are you driving?

2002 blazer, 2 door, 6 cyl

You do not have a speedometer cable. The speedometer uses an electronic sensor in the back of the transmission (2wd) or transfer case (4wd).

Your problem is likely the cruise and/or throttle cable resting on the PCV hose and transmitting the noise from the PCV valve in through the throttle cable.