Noises problem
1996 Ford F150 V8 Four Wheel Drive Automatic 186000 miles

My 96 f150 with a 5.8l has a very loud whining noise. I can't tell where it's coming from. I jsut had a trur dual exhaust system put on it about two weeks ago. Now the whining doesn't do it at idle only when i am accelerating or when I let off the gas with the engine under a load and it goes away if i am coasting in neutral.