It was a leaf stuck in the fan. The fan is under the plastic scuttle cover. The wiper arms have to come off and I used a puller to get the left one off but not enough room on the drivers side as the bonnet was in the way so put a bit of pressure under the arm with a wide screw driver put the nut on and tapped with a hammer and off it came at the second hit. Typical car makers, put everything on dry and mix different metals and the reaction 'welds' them together. Cleaned the tapered splines and greased them and twenty minutes later all done with a quiet fan.
