Freeze plug, AKA "core plug", is a good suspect at the mileage you listed, especially if the antifreeze wasn't changed every two years. Acids build up in the coolant when the additives wear out in about two years.
A leak this fast should be easy to locate. A pressure test might make the job easier. If the leak is too slow, you can consider adding a small bottle of dark purple dye to the coolant, then check a day or two later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. Be sure to check for the dye inside the tail pipe.
Auto parts stores will have the dye for the fluid being tested, and those that rent or borrow tools should have a black light.
Tuesday, August 1st, 2017 AT 8:01 PM
