I have a 97 eclipse with 221000 miles everything has been taken care of for the most part but the oil sending unit started to leak and it sat for a while(i did not drive it at all) i bought the new sending unit and changed the oil plus added a quart of lucas. later that day it had a very slight knock but only when i hit over 4000rpms. so for almost a week i drove it under 4000 rpms and then one morning it was doing the same thing untill i was driving home and i was in 4th gear and the oil light came on and i lost all aceleration and white smoke blew out the back of the car. I had it towed home and then i tried to start it after i filled it with oil again and it turned over and ran but after about 30 seconds to a min it shut down again. what could be wrong?