FIAT PUNTO GO 1.2. ITS WINTER TIME AND WEN ACCELERATING MAKING THE COOLANT FLOW I CAN HEAR SOUND OF GUSHING WATER AS IF ITS SLUSH. I WAS WONDERING IF ITS EITHER FROZEN COOLANT OR AN AIR LOCK... SHUD I DRAIN? SHUD I BLEED? SHUD I BURB BY RUNNING WITH RADIATOR CAP OFF? THANKS