Is it on the drivers side or passenger side on the bottom? What engine do you have? Could be a bad bearing in the alternator, ac unit, power steering pump, idler pulley because I don't know what you were touching. I've had alternators make a whining. Could even be a water pump going bad. Take it back to the shop and point the componet out to the tech and tell him it only does it cold. You might have to leave it over night so they can catch it making the noise. If nothing else, take it to autozone and have one of the desk guys come out and you can point to the componet. He will tell you what your looking at. If I was you, I'd buy a Chiltons or Haynes manual at the parts store and study up so you can talk the talk with the repair guy. Good luck.