I’ve refently bought a 1.8T Golf and the water keeps boiling over but the engine temp won’t go over a touch over 90 degrees, car can be sat there for ages on tick over and it will not go over 90 degrees but when you turn the engine off you can hear the water boiling over and pressure through the system from the expansion tank. But undoing the watter bottle to release the pressure and the water will spit out too. Water pump has just been changed on it too. Just wondering whether they run with a presurized water system or is this a posssibe head gasket job? There’s no milky gunk in the water bottle and no **** in the oil. Hence why I don’t think it’s the head gasket. No oil leaks anywhere either