Agree with Kev, the engine sounds normal for a D5 in those videos. Also agree on needing a coolant change.
I’ll add a link to a thread on my previous V70 I did which shows a coolant change, power steering fluid replacement, gearbox oil changes etc. for info as it might help with basic maintenance tasks. That was a euro 4 D5 but the tasks are similar on the euro 5.
https://www.volvoforums.org.uk/showthread.php?t=302878