I've not 'done' anything to it. Using the car for work yesterday and it just didn't seem right - a bit lethargic but I was just putting it down to the heat of the day, plus a funny 'wet fart' type noise after start up.
When I got home I had a look under the bonnet with it running and it didn't seem very responsive to throttle and the pulleys appeared to be labouring a bit. Maybe its just me being paranoid though. When I pushed down on the aux belt the tension semed to be a bit slack but I forgot to check it agains the A and B marks on the cover - will do that tonight.
With it being so close to having the engine pulled anyway, I don't want to take excessive chances - just need it to get to yours on Saturday!