Astra J 1.4T Overheating

[Bear]

Hi all looking for advice

My Astra has recently started having overheating problems, Its had a new Thermostat and the waterpump has been removed and checked and is functioning correctly but it still seems to overheat, It'll sit happily on 90 during idle but after 3-5 minutes of driving it'll overheat and creep upto the 110-130 mark and advise the engine has overheated and to idle the engine. I was wondering if anyone else has had an issue like this and what my next steps should be?

[Jpbroad1970]

Airlock maybe or coolant temperature sensor maybe?

[Bear]

Airlock maybe or coolant temperature sensor maybe?

Coolant Temp Sensor is built into the thermostat from what i can see, Every time I've had to replace coolant I've vacuum bled it afterwards. I'm really picking my brain on what else it could be

[Bear]

UPDATE: After checking the breather/return pipe we've uncovered it had been glued back together (by a previous owner) after being broken and then caused the pipe to block, causing the engine to overheat