Was driving round today looked down and noticed my temp gauge was on red.its done this once before.car drives normal and doesnt seem to be overheating.has just had mot and service.

did a guage test and the temp guage needle didnt go back to normal postion when they spin to the left if that nakes sense.

what could be causing this??

2006 focus 1.6 petrol

Could be a stuck thermostat, but the needle should have returned back down, if it didnt, even on the gauge test, it could have been receving odd information from the thermo, so start with that, check that its not stuck, and replace as necessary.

also check the wiring to the temp sensor that it is not earthing

Check the coolant bottle lid is sealing properly.