I’ve seen a lot of posts about timing chain failures on the BMW N47 engine, so I did a proactive replacement on my 520d. I bought a full BMW N47 timing chain kit that included upgraded guides and a reinforced tensioner. The parts looked high quality, and it’s been a few thousand miles now with zero issues. A job worth doing before any major damage occurs. If you're noticing ticking or rough idling, don’t wait—get it sorted.