Do you have an OBD test meter? My Maxiscan has a live running function that displays many readings that you can check. I had a Plus8 . The fan kicked in a lot! Basically the MMC aluminium rad , in my view, was only just capable to maintain coolant temp to an ok level. Hot weather, slow traffic etc led to the fan needed. I had done runs with little mods but it was still kicking in too often. No overheating as the fan did its job. Gauge readings were at expected levels reported for Plus8's. Summer v winter showed clear differences in coolant temp.
I used the Maxiscan to get readings of coolant temp that the system fed to the ECU. These matched the dash gauge so that was assumed ok. A thermometer used on the rad, top hose backed up the readings of gauge and Maxiscan.
On two occasions over 50k miles the fan failed, due to the fuse blowing. I stopped before problems. I hadn't heard the fan when expected and the gauge showed higher than normal.
