Ok,here's one. I own a 1985 sd w/ 198 k on it. Runs really well, idle, etc. Valves adjusted, etc. Only problem is I can be tracked from a stop by the white cloud behind me. Mainly when warm and more pronounced after a stop. I just checked intake side of turbo and shaft has very little if any forward and backward play, but can wiggle shaft top/bottom/side to side- how much play is normal? ALSO, seems to rotate kinda stiff. If I reach inside intake end and try to turn it will; but it will not "spin freely", if I try to spin it. I am thinking maybe turbo seal? Oil separator is sealed. Intake side of turbo has little wet oil in it, but don't think it's that much. Garage drove it around block and pronounced rings are gone. Hard time believing that one..OPEN FOR IDEAS!