It makes the sound only occasionally.
My car makes a whopping noise when I am at a stoplight. on 2005 Acura TSX
It could be many things, unfortunately and without hearing the noise first hand or being able to do some basic diagnostic tests or be able to drive the car, its hard to say what the source of the noise may be. Try to determine where the noise is coming from front of the engine passenger side of the engine driver's side of the engine? When the engine is cold or warmed up, only when the a/c is on or steering being operated.