gill astra light on dash man with spaner keep coming up?

Hello
I just got a astra 1.6/8v it will idle for about 10/15 mins then the light comes on and then power lose and will not start for about 20 mins then after the light will come back on.......
I have done the following
cleaned throttle body
new cam sensor
new crank sensor
cleaned EGR
new temp sensor

gill