Clunking would make me think it's the timing chain. Does it do it at idle? Does it sound like it's coming from the passengers side? Listen close to the valve cover on that side.Hey Guy's I have this load thumping noise on my 96 Sentra that seems to be coming from one of the mounts? It's very strange because it drives very smooth and handles great for a car it's size. What is typical with these car's? I thought the Mount's looked decent when I changed the engine and tranny???