i bought my car used, it always had a rattle noise sounded like it came fron the engine, a couple of weeks ago my low oil pressure light starting coming on but the oil level was full, last night it died on a hwy, it cranked back up but would go past 30, not it won't go at all none of the guages are on but there was a little white smoke, i put more oil in the car which means it has too much, what should i do?