Hi All

Partner has a 2015 Astra on around 87k miles. Sudden raid in engine temperature when she was out in it. She got it home (very short distance). I checked and alas, no water or oil, no idea how long for. I suspect Cylinder Head Gasket has gone, as when I filled the water reservoir, it began seeping from the side of the engine block. 
assuming we elect to get it back on the road, what is the Lilly cost? Are we in the hundreds or thousands? 
 

Thanks. 

Simon

Its a tough one and can only be diagnose correctly by carrying out some tests and then dismantling to determine the damage

Got to be worth at least running tests to see if it is the head gasket or water pump at fault - you may be surprised by the cheap cost if it is waterpump
However, loss of oil may be because it hasn't been topped up in a while and may just need an oil change (looking at it optimistically) 

Let us know what you find out