My 2003 Toyota Corolla, used, is making a noise like sliding sand from the left to the right of the dashboard when I make a left hand turn and the air conditioning is on… what could this noise be?
Sounds like something has gotten into the air ducts. You may have to take the air-ducts appart to find out what and remove it.
Are you sure it is not water moving back and forth?
Yeah, I agree that it is likely to be water that has been trapped by a blocked A/C drain.
My vote is for either a coin or a Lego piece in one of the airducts. Very common.
I did hear some water at times, although most of the time it sounds like sand… and now today, I noticed a few water droplets on the carpeted driver side console underneath the dashboard… and the carpeting under my vinyl car mats on both driver side and passenger side is soaked with water! this must have been going on awhile…so, maybe it is a blocked a/c drain? and now is leaking out another way? I hope it’s not an expensive job…