The 1980 300 TD that I just purchased was run low on oil due to careless Quickie-boob service . The prior owner tells me that the engine now has a knock . The engine has 184k ,but still runs . I have not tried to start it as I do not want to do any further damage . My question is ,has any one had simular situations ? I am able to do the rebuild work myself but have not been into a Mercedes engine . I have heard all sorts of horror stories about million dollar parts . Would it be worth going for the rebuild , or can I expect more than bottom end damage . Would it be better to shop for a used engine ,do a complete overhaul , or just check the bottom end and do crank and bearings ? Does any one have a good Idea what parts will run ? Lotta speculation here but give me your opinion . I am not looking to buid a space rocket ,just a driver for a couple of years . Thanks