I've just given my bike a right good seeing to: new chain, cassette, derailleur, chainring, cleaned and greased the bearings in the pedals, BB, both hubs. New tyres: SB8s after 2 years on PR Cinders, wowsers. I even cleaned the frame, which almost never happens.
Everything's working beautifully, except I can't get rid of the clicking in the pedal bearings. They're 9 year old V8s and they still get the job done perfectly: they're attached to cranks, and when I push down on them, they go round and the bike moves. And they're grippy, so my feet don't slip off. The noise makes no difference whatsoever to the function.
They've probably got another 9 years of doing this job perfectly, and I could even get some new pins to make them grippier.
But there's the noise. New V8s just for a bit of piece and quiet? New v12s for longer-lasting piece and quiet?