13 minutes ago, SometimesStuff said:
Not to hand, I could probably get a cheap Intel one to test against, it didn't make this noise when it was new, but that was a long time ago! I didn't think about checking that, so I shall look into it! Would it be worth getting a new AIO if that is the cause? That is something within my range of replacing
Depending on when you got it you may be covered by warranty, otherwise yeah a new cooler would be needed. Air coolers wouldn't break down like this so if you do verify that you've got a pump issue, a high quality air cooler would be a good investment instead.