It starts mostly at 59mph (1400rpm) if you accelerate it will stop or if you decelerate it will stop. The sounds continues if you maintain that speed. It has made the noise at 30mph if on an incline. Do you know what is causing the noise? Dealership replaced shift cable it did not fix noise. They are starting a "Report" with GM I will let you know if they find a solution.I think I know what you talking about i might have the same noise sounds liek a some kind ow wine nose and goes away when rpm goes up.
Sounds as though it could be your "Cylinder Deactivation" kicking in. Mine sounds like a motorcycle when it's chugging on 4 cylinders & even moreso since I put on a performance deeper time muffler in back.sounds like a motor cycle at 1400 RPMS Dealership can't figure out the problem. suggestions as to what the problem may be is appreciated.