KevinH said:
It's possible that either the alternator or belt tensioner bearings are worn and maybe squealing.
Have a further listen to see if you can pinpoint where the noise is coming from.
I would say it's very difficult to reset the balance chain without removing the timing chain. I think the balance chain guides would probably have to be removed but the top guide sits behind the two timing chain guides so the bolts are rather inaccessible.
You maybe able to get enough slack on the chain to reposition it by removing the BC tensioner (make sure you have the pin to lock it when resetting it before refitting) and the two lower guides.
I'm wondering, having read through the thread again..............
mattg did you reset the balance chain tensioner when you refitted the water pump sprocket? it may have popped out a bit when the chain pressure was off, thus causing too much tensio on the b/chain. Just a thought.