imho good old Nintendo have released Wiis with some poorly made drvies.
My own Wii is away getting it's drive replaced, I never used any loaders, but had a mod chip fitted. I have seen hundreds of people complaining about noise from the drive that is "unusual".
If you google and go to youtube there are all sorts of vids of this. Some are people simply tightning or loosening a few screws to resolve the issue.
This happens to people that have chips, don't have chips use the loader or don't. Some are lucky and seem to have real quality drives that make the same read noise no matter what you chuck at them. Some drives this happens within a week of people getting them.
It is a HUGE mostly untalked about problem because the people devide themselves into groups.
EG: Here we have people assuming it's a loader etc. Other places there are people with the exact same problem blaming the fact they got it chipped etc.
It is the drives themselves, why do I think this?
It is the ONLY common factor in ALL of this.
btw, you can't fix something a loader does by adjusting screws
Well my 2 cents, and yes Nintendo have had faults before recalling thousands of NES in USA because of bad connectors causing loading problems so maybe they got it a bit wrong again. No one has documented the drive batches that cause this, or is it them all