Vauxhall Astra engine cut off

Cooling fan does not normally cut in until temp gauge is very near boiling / in the red so cant see the tie in .Need more info on fault you are asking about , what happens when it stops , try to re start etc .

Thanks for your reply.once the engine cuts off it won't restart again until about half an hour later. the temperature gauge only shows normal when the engine cuts off. the coolant is leaving and returning to the radiator. any of your suggestions about this will be much appreciated

engine won't restart for about a half an hour after cut off, although it does turn over but won't fire the coolant is leaving and returning to the radiator any help with this problem will be much appreciated

If you are not losing coolant , overheating or pressurising the coolant system I would check / replace crank sensor