In that area, either you are hearing an exhaust leak or the fuel pump running. Can you hear the noise when you turn the key on without starting the engine just for a second or two? If so, that is the pump. If not, check for an exhaust leak where the different components join together. Look for spots that are covered with black soot from the leak.
Let me know what you find.
Joe
Monday, May 18th, 2009 AT 7:33 AM