I have a 2006 cobalt, it has 80,000 miles on it. It started just making a kinda of a whinning/roaring noise under the hood. Its fine til I get up around 40mph and the noise doesnt change when I shift my manual 5 spd trans or let off the gas. But when it drops below 30 mph the noise disappears? When I do get above 70 the noise disappears. It has good tires. The noise is comming from the front engine or transmission area. Could my fluid be low on my manual trans? Front wheel Bearing?? Thanks for anyones help.