overheating

Unfortunately this is a common problem do to a manufacture defect. What I mean is that GM used a bad design in the intake gasket. GM used a intake gasket that that had plastic in it. What would happen is the plastic would break down due to heat and the rubber that actually sealed the intake manifold would loose it's support to seal. Who ever does the repair make sure the shop uses a FELPRO gasket. The FELPRO gasket part number has to have a T at the end of the number. The T stands for trouble solver. Meaning that instead of plastic FELPRO redesigned the gasket with steel instead of plastic. The repair is not inexpensive unfortunately. Hopefully you haven't done any damage to the engine. If you would have had the engine serviced by a qualified tech he would have noticed the coolant reservoir or the radiator was low on coolant. Only a tech with experience would know about this problem. I'm sorry for the bad news. I hope the new year goes better. If you need more info to get the FELPRO part number and a reasonable cost of the repair. Contact me at jmgrhm30@gmail.com.