hello rob,

the knocking problem you got there is I think a drive shaft. you have to jack the car up and see when you turn the wheel forward and backwards if the drive shaft do it to. maybe you can see that the shaft goes up and down. but the knocking problem is coming from a knackerd drive shaft. and more the flexibal parts of the shaft (if you know what I mean).

about the fan problem...check the relais. and check the relais holder maybe its burned a little. or melted.

best regards,