Crank pulleys

[titch]

Have a look at the belt run from the drivers wheel arch, mine was bouncing at the longest point between the crank pulley and the aircon compressor.

I just released the spring loaded tensioner, the manual one is held by an allen key and there is a square drive in it, that a 1/4 inch ratchet will fit in, tension the belt up with that and then release the spring loaded one.

Just have a look at the spring loaded tensioner with the car running and see if it is bouncing loads.