2012 Terrain squealing from overflow tank

[eenterline]

Have a 2012 GMC Terrain with 2015 engine with 58K miles.
Never had an issue with overheating until recently. Pressure check has no leaks at 2mins. Have flushed entire system. Have replaced thermostat, overflow cap, water pump, and radiator. With 1/2hr idling heat gauge sits one tick before half (car normal) sometimes gets close to half. When engine is warm giving it gas results in a high pitch squeal from overflow with steam, i.e. too much pressure. Hose into the thermostat is hard like it's not flowing through
thermostat. Have tested thermostat in pot on stove, opens at temp.

I am stumped on this one. Any help appreciated.

[Hankrigby]

Originally Posted by eenterline

Have a 2012 GMC Terrain with 2015 engine with 58K miles.
Never had an issue with overheating until recently. Pressure check has no leaks at 2mins. Have flushed entire system. Have replaced thermostat, overflow cap, water pump, and radiator. With 1/2hr idling heat gauge sits one tick before half (car normal) sometimes gets close to half. When engine is warm giving it gas results in a high pitch squeal from overflow with steam, i.e. too much pressure. Hose into the thermostat is hard like it's not flowing through
thermostat. Have tested thermostat in pot on stove, opens at temp.

I am stumped on this one. Any help appreciated.

The whistling tells me cracked over flow tank. It could be cracked right were the cap seats. You could also have a faulty call even though it's new.

I've been a mechanic for nearly two decades. I'd say anything 10% of new parts I've replaced were faulty.

Also smell around the over flow tank. Does it smell like coolant or engine exhaust. If you smell exhaust the chilling system isn't your problem.

[eenterline]

Thanks Hank! Waiting on a new overflow to come in tomorrow. To your point of smelling exhaust what am I looking at? Didn't smell exhaust but curious. Car purrs like a kitten .