UK Car Repair: RENAULT 5 GT TURBO, renault 5 gt, head gasket

Question
HELLO, IN NEED OF SECOND OPINION MY CAR ALL OF A SUDDEN DECIDED TO LOSE A LOT OF WATER, THIS HAPPENED IN A PERIOD OF ABOUT 5 HOURS FROM LEAVING IT FROM A JOURNEY WHERE IT WAS FINE AND RETURNING TO USE IT AGAIN JUST OVER 5 HOURS LATER, I INSTANTLY NOTICED HOW IT WAS ABOUT TO OVER HEAT SO I STOPPED.
INSTANTLY HEAD GASKET COMES TO MIND, BUT WHAT CONFUSES ME IS HOW IT IS ONLY DUMPING ITS WATER IN THE PERIOD OF WHEN IT IS LEFT STATIONARY. I HAVE REPLACED RAD WEEKS AGO AND EVERYTHING GREAT UNTILL NOW. IS THERE ANYWHERE ELSE WATER COULD ENTER EXHAUST SYSTEM, AS IT APPEARS TO HAVE HOSE FROM PUMP TO TURBO? FAILING THAT WHAT MIGHT BE ADVISABLE TO CHECK AS I AM VERY STUMPED, HEATERS WORK ETC, THE CAR HAD ENGINE REBUILD 6K AGO ASWELL. ANY OTHER OPTIONS WOULD BE MOST WELCOME!

Answer
Where did the water leak from, the exhaust? From your description it may be a "loose" cylinder head and when hot it expands and seals then, as it cools down, it seeps. My first suggestion would be to re torque the cylinder head then add some "BARS LEAK" or equivelent to the coolant.