i have a 06 Pontiac Montana ,and when i go over 70 mph,i makes a buzzing...

[zack d]

...noise,what is it? it sound like it is coming from the dash board ..
it sounds like it is coming from the dash board ,it dose not do it every time ..

 

[PenelopeM]

You are sure that it's not the auto-destruct, right? (Just kidding.)

Could it be a loose connector, either electrical (like a wire that runs to some gauge) or mechanical (like a fastener....screw, bolt, something)?

 

[melsg5]

is the steering wheel shaking slightly when this happens? if so you probably need your wheels balanced.