Check the stretch, its easy and it will tell you if the chains is bad.
Do a search for instructions, the only thing that varies is the location of the marks on the cam and cam tower. Align them, then not the position of the balancer -- read the degree mark.
More than 8 degrees is a bad chain.
Chain tensioner can be checked by pulling the valve cover with the engine warm and just shut off (right side on V engines) and pushing the tensioner rail (the one that pivots on the bottom) back. If it goes easily, it's shot. If you have to push hard to get it to move, and it moves slowly, it's fine.
Very long chain and/or bad tensioner will cause the chain to slap on the slack (right hand) side, eventually it will clank on the head or cam cover. You won't mistake that for anything except a bad rod.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!