Coolant Passing Through Combustion Chamber

What is your question?

Went to mechanic for overheating, exhaust smoke and error codes (P0420, P0299). After diagnosis, mechanic found coolant passing through combustion chamber, which potentially is causing catalytic converter error codes. Was told engine repair is non-existing, just get a new engine ($15K fix). Mechanic said that coolant leak isn't a head gasket issue (they tested). Question: is there any other way to fix this coolant leak issue other than getting a new engine (or a newer car)?

How long has your 2014 Ford Escape had this problem?

A few days