CROWN VICTORIA PROBLEM YEAR 99

HELLO I HAVE A 99 CROWN VIC AND IT HAS DEVELOPED A SMALL LEAK OF WATER AND SOMETIMES THE TEMP GAUGE SWINGS TO THE HOT SIDE BUT WHEN YOU PUSH THE EXCELLERATOR TO THE FLOOR IT GOES DOWN THE FAN IS WORKING WHAT COULD IT BE?

is the car running when you push the throttle to make the temp go down? if so it could be poor water flow due to a restriction like thermostat sticking,radiator clogged or old water pump not pushing water at idle.where is the leak?

my 01 p71 was doing the same thing for a bit so i swapped to a 180 deg thermostat and its been mint ever since. its a cheap and easy thing to swap.