My car shut down on me on the interstate one night there was no sounds at all coming from the car and I was told that the alternator may be bad. It was tested and found to be bad and had also killed a couple cells in my battery, which also had to be replaced. After repairs, the car developed this loud knocking sound in the engine. And plumes of white smoke and exhaust poured from the tailpipe. Has the car thrown a rod? And if so, what are my least pricey options for repairs?