So now I have two cars with seemingly bad engines...I want to know what it will take to fix them. The most recent is my 1983 200D. A bolt came out of the engine, and it leaked out most of the oil before I noticed a knocking and stopped and found out. I've remedied the problem, filled up with fresh oil, even adjusted the valves, and the engine still sounds absolutely terrible. Same story with my 1982 300CD, except Some different cause I don't remember.

Here's a video so you can hear the sound - what can I do??
YouTube - 200D engine knock