My car battery would drain if it sat to long and then I would have to jump it, this kept getting worse and worse till it would not start if left off for 12 hours. The car sat in my driveway for a little less than a month till I had the money for a new battery. When I jump started the car to go get a new battery the engine was making a weird noise. When I turned off the car the engine didn't stop right away and sputtered out after a few seconds. When I put in the new battery as soon as I hooked it up the car started to turn over without a key in it. Do I need to replace the starter? Or what is my issue?