Well redoing the cpu heatsink has knocked off around 10c, it's now sitting at 41c where as last night it was at 52c.
I was never happy with the way the case fans were connected through splitters, with wires going everywhere. So this has cleaned that up. And I can turn them down when I'm not doing anything that requires them.
I put the sensor just above the cpu in the end. Thanks for the advice.