Will I be in trouble if I am going to take the car?

My son's friend's grandmother moved to another state and said she had a car and was going to give me her other car that needed repairs. They towed it to me but did not give a clear title saying she still owed money on a loan she had gotten but would take care of it at the beginning of September. I talked with her and she said she's giving it to her grandson. I contacted the grandson and he said he'd pick it up this past weekend. He did not and will not answer any messages or emails on social networking site where he is on a social networking site daily. I am moving and the car has to go. There is nothing I can do with it because I do not have a title. I do not know where she got the loan so I can turn the car into them.