Water pump squeal

[shadowfax]

After the refurb on my alt last month, there was a grinding noise. Checked if from the refurbed item and with belt off (HC engine) no noise. Hand turning the water pump pulley, nothing heard atall. Noise from alt was worse when cold so by time drove to autoelecs, it also was noiseless. After a few weeks I took it back, removed from the car, today and he could tell the bearings werent right so agreed to fix foc. Returned to collect and he told me when they changed bearings again the noise got worse, so he gave me one that looks just like mine - original magnetti marelli, which they painted over when they refurbed it last time - and gave me that in exchange and said it is fine.

Got home, and .... noise is the same. Took belt off, noise vanishes. Rang. He said it must be water pump so check for play. Did. Slight 'lift' seems present. Replaced belt a little tighter cos had it very loose before. Squealed like a stuck pig and after 20 seconds or so, became silent. But that darned rattle is still audible.

No water leaks atall.

Ideas?

Like for one, how do I check that the pulleys are inline so I aint putting unnecessary strain on anywhere? The belt really isnt that tight - there's a good inch defelection.