when i drive my car for about 30 mins and say am in traffic and need to come to a stop, i put it in nutueral, my car seems to make a reving sound basically on the revs it goes to 2000 revs then back down does that untill i put it in D then move on. is that normal or do i have a problem, ive heard people say its kooling down the turbo,the oils are lubricating it so it doesnt sees up. but to me i dont like the sound doesnt sound healthy. does this happen to any 1 else? what could be the problem or is it completly normal. is it becouse it a auto? thankys people