Yesterday I took the car to Sears for a check. Finally the mechanic heard the noise and replaced a hose connected to the drier.
After driving home for about 30 minutes, I did not hear any noise and the air conditioner was working great.
How lucky I am that I do not have to go back to Sears . . . . .
Thank you so much to all of you for your recommendations.
Keep up with the good work !
Friendly format provided to inquire about automotive a/c systems.