I have a loud roaring sound from engine and I cant pinpoint it, took to ford dealer and he said vacuum leak somewhere but not to worry, but it has gotten louder and more often, and also engine hesitates now when I step on gas.
It does sound like it could be a vacuum leak. Have you checked for any bad vacuum lines or intake leaks? Have you checked the intake hose from the mass air flow unit to the throttle body? Let me know what you find and we will go from there.