Thank you so much for the reply
the belt lower down in the engine (not alternator) feels a bit tight, but the noise started after driving through a lot of puddles to get to work
Are the bearings in the pulleys down there easy to replace? Seems like it would be a faff to get in there
Did you figure this out? my engine is doing similar, not from exhaust as mentioned in this thread but from side of engine, dont think its timing chain, seems like its one of the pulleys