I was cruising at a good rate of speed when all of a sudden I had a lot of white smoke coming out from the hood. Soon after, It started knocking horrendously.. it sounded like it was coming more from the upper part of the engine, and lost a lot of power. Full throttle barely moved the car at that point so I let it sit in my driveway for a while. Went out to start it today and I cant even keep it running.. I've tried working the throttle just to see if I can keep it going but its pouring out lots of white smoke still and I am really not too sure what I am dealing with here. A little history.. The car has run down to a quart of oil before, it has real bad trans and oil fluid leaks.. probably from the same spot but I cannot get a line of sight of where it's at. I've been thinking it might be my lifters or valves or something. I really hope its not a fried piston. Any ideas?