1997 Ford Escort

I HAD MY THERMOSTAT CHANGE AT THE FORD DEALERSHIP BUT I STILL SMELL ANTI FREEZE. THE NEEDLE IS STILL GOING PASS THE MIDDLE, AN INDICATION IS STILL RUNNING HOT BUT NOT HOT ENOUGH TO BE IN THE RED. I HAVE TAKEN IT BACK SEVERAL TIME THEY SAY NOTHING WRONG. MY QUESTION IS IF I HAVE A LEAK WHERE MOISTURE IS GETTING INTO THE PISTONS, IS THERE ANYTHING I CAN DO TO SEAL IT OR AM I LOOKING AT A POSSIBLE BLOWN HEAD GASKET? I APOLOGIZE FOR TYPING ALL CAPS I'M NOT YELLING JUST A BAD HABIT FOR SOMEONE NOT VERY FAMILAR WITH THE KEYBOARD.

THANKS TARSHA PETERS