One problem related to engine cooling system has been reported for the 1997 GMC Sierra. The most recently reported issues are listed below.
Dexcool is coolant used in the system, but it destroys the cooling system when mixed with air. GMC will not recognize the fact that it put dexcool in the system and when the waterpump developed a weephole the air that got in destroyed the cooling system. This is GMC's and dexcool's fault.