Hello, my 95 disco had a rather loud knocking sound which sounded like it was coming from the bottom end of the engine, so i replaced it with a 4.0 short block. The truck is still making the knocking sound even with teh new engine, so i guess it wasnt the engine knocking. I thought it might be the catalytic converters but the knocking seemed so loud i didnt think it could be them. The truck makes the knocking sound at idle and also as the engine revs so does the knocking. The knocking sounds like a tin can rattle sometimes, which makes me lean towards the cats. What else could this knocking be if its not in the engine?