Need advice

My fiance bought a used truck a few months back and it gives him so many problems he constantly spending money and its a hunk of junk now another problem is wrong costing 500$ I suggested he trade it in to the man he brought from for something else snd let him know he cant keep it because it doesn't seem reliable and he drives a hour to work everyday. Problem is that he doesn't want to. So i don't wanna make him do that but we got so much other things financially to worry About he said a mechanic would let him make payments but it still seems dumb to me