Coolant level

[Big Dave2]

first check the header tank see what the level is, common for the sensor to go faulty.

But it's a 50/50 mix of this https://www.autovaux.co.uk/93170402-anti...gm93170402

Is it normal to be topping it up? Never had to in any previous car?

Me neither. But I've had my Astra-J 2.0 CDTi for 5 and a half years now, and every month I have to add a drop of water/coolant into the header tank as it's dropped by approx. 10mm. Garage can't find any leaks either.