Chevrolet Repair: Block heater leaking coolant, radiator pressure tester, chevy blazer

Question
We replaced the engine in our '97 Chevy blazer. 4.3l v6. The engine is a reman. The vehicle is going up to Alaska so we wanted a core heater I purchased from a GM supplier that is in the freeze plug on the right side of the motor ( driver side ). All other indications are normal but the leaking of coolant from around the core heater. It seems to only bre prevalent after operation, pressure builds. What are any options short of removing the core heater to stop this leaking and be able to use the core heater?

Thanks.

Answer
HI CHRIS, TO DO THIS RIGHT YOU SHOULD REMOVE THE PLUG AND CK THE SEAL AROUND IT.IT IS MORE THEN LIKELY DISTORTED OR SPLIT.IT IS PROBABLY NOT EASY TO GET AT IS IT ?? IF YOU HAVE A RADIATOR PRESSURE TESTER YOU COULD PRESSURIZE THE SYSTEM AND LOOK AT THIS PLUG VERY CAREFUULY AND SEE IF IT IS LEAKING AROUND THE SEAL AREA OR THE HEATER CENTER ITSELF..YOUR LAST OPTION AND [NOT MINE]WOULD BE TO USE STOP LEAK IF THE LEAK IS SMALL ENOUGH...YOU HAVE A 50-50 SHOT WITH THAT STUFF. I HOPE THIS HELPS YOU,IF YOU NEED MORE INFO GET BACK TO ME... TOM...