Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
If you are going through coolant without any external leaks then the problem is either a headgasket or intake gasket. Most likely a headgasket since it is causing overheating, you will have to bring the vehicle to a shop so they can perform a pressure test to verify it is the problem. Let me know if you have more questions, thanks.