I watched this before, and thought "That's a good bit of advice, I will have to remember that". And guess what!... I completely forgot all about it :-)
My crank pully failed around 3 years back. As you say I noticed it was making a right old noise. If you pour some water over it whilst the engine is running it will quite it down momentary helping you diagnose the problem.. The tensioner was a real pain to change just like yours 👍👍
