2012 GMC Terrain 3.0L V6 Flex fuel with 207k miles
Intermittent coolant usage with leak source not obvious. It doesn't appear to be mixing with the engine or transmission oil. No external leaks noticed. No sign of coolant leakage at water pump weap hole. All hoses seem to be sound including those at the firewall, bypass, etc. Reservoir tank seems fine. Next step is to pressure test I think. Surge tank cap is rated to 15 psi. The top of the pressure tank has a vent hole so does the adapter cap block this hole? Can anyone provide the adapter kit # to use for this vehicle or other recommendations?