Outer Limits 4x4 Board

hi guys i need some advice. i have a 2wd 2004 holden rodeo with the 3l turbo diesel motor in it. a few weeks ago the sump plug fell out, and lost all oil in the motor on my way home from work. i had to pull over and get towed. got some oil back in it and it is running, but there is a rather loud tapping/ticking noise coming from the motor now. ive been told maybe the lifters need adjusting now. there is no loss of power from it and there is no excess smoke. just seeing if anybody has any suggestions as to what it may be?
thanks for any advice