Chevy Tracker 2005 ZR 2 engine sounds?

On a ZR2 does anyone know any specific reasons why the car would develop a slight humming sound that is audible over the sound of the engine? The car in question also lost some power since new when going uphill. Local Chevrolet techs apparently said they don't mess with it as they don't know what it is and the engine is a Suzuki engine. They would have to take the engine apart at a cost of over $2000 and not guarantee any results. They also said that the problem is also connected to the electrical system, possibly. The car blew out the fuse to the cd player cigaret lighter main console 5 times in the past 2 years.