If it is coming from the w/p, it is probably the fan clutch. Have you tried any belt dressing on the belt? One thing I did to test my brother's fan clutch was while it is running to spray just the smallest amount of lubricant on the fan clutch. If it shuts up after this, than the clutch is bad. You wouldn't be able to get any lub in the w/p bearings becasue they're far enough in that none would reach them so it would be limited to the clutch. Be careful when doing this becasue cintrifugal force will throw it and you don't want to get any on the belt because that might cause it to slip. Let us know what it ends up being.
Thanks
David

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2000 Honda Accord V6 137k miles

1972 300SEL 4.5 98k miles

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