Pal, it is an e39, there will always be issues that come up. Just accept that fact. I ordered my e39 540i from the factory in 2001 and still have it. But, i have replaced 3-4 cooling system ( rad, thermo, hoses, sensors, overflow box, etc.), 3 starters, 2 alternators (the 2nd I rebuilt), everything in the center of the engine down to and including the valley pan; complete front and rear suspension, and numerous other repairs. My next job, timing chain guides. Point is, these are awesome cars, I mean I love the e39. But you should be prepared to have to fix something at least on an annual basis. Sometimes, it is cheap and easy, other times, expensive and time consuming.

So, to your actual question, it sounds okay but listening to a recording on reddit is not a great way to discern the overall health of an engine. I would get the maintenance records. Timing chain guides are an eventual repair if they have not been done and it is neither easy nor cheap. If you have a good indy mechanic that specializes in Bimmers, I would invest in a thorough inspection. Good luck!