BANG, CRACK, CRUNCH and SQUEEL are the noises coming from my crank area, replaced my BB earlier this year.
Could it have gone again? Could it be my frayed derailleur cable?
Do the cranks wobble if you grab the arms and try to move them perpendicular to the axis of the BB crank?
If you unship the chain and gently spin the cranks is the result anything other than a butter-smooth rotation?
Have you got a stupid FSA external BB that's been within 500m of a puddle or atmospheric moisture?
Have you got a stupid BB30 bottom bracket?
If the answer to any of those questions is yes, then your BB may have gone again. Sorry about that.
It's blatently fudged, it's GXP, I could feel it moving from side to side.
Not on every rotation but perhaps once a minute.
There is the chance that if it's sliding then the non-spider crank arm has worked its way off the splines, and by retightening and torquing it'll be alright. If it's notchy or gritty as you spin it then it's probably hosed.