this might be an issue, when the motor gets really hot the fan turns on but should the cooling fan should turn on all the time or at a certain temperature?

The fan will cut in when the temp gets about 10 to 20 degrees above normal temp, so normal.

Mine usually kicks on when the temp meter hits 4 bars.

Mine usually kicks on when the temp meter hits 4 bars.

Thats right where mine hits too. I took the time and blew out the radiator fins and checked it for bug goo while I was changing the oil and doing a 50 hr service as well.
It seemed it was kicking on a bit more frequently than it had been and my coolant hasn't lost a hair level wise.