Back of motor, silver round thing with what looks to be a vac line going into top of it near the throttle cable? Mine makes a buzzing sound when the key is on but car not running. Does that thing stay on all the time? What is it?

 

Sounds to me like the throttle body being energized. Does the sound go away after you start?

 

can't tell if it is or not over the motor noise.

 

Can you feel the noise, vibrating, then start it to see if it quits

 

I tried that, with car turn on, butn ot running I can feel it. But once the car is running I really can't tell since the motor naturally is a little shakey, what ever you want to day.