What 10 owners told NHTSA about the 2020 Chevrolet Sonic

Engine Cooling System (Thermostat Housing / Water Outlet) The vehicle suffered a premature structural failure of the factory engine coolant thermostat housing. The component, which is manufactured from a fragile plastic composite, cracked completely open without warning, causing an immediate, rapid loss of engine coolant. This constitutes a severe safety hazard. A sudden, catastrophic loss of engine coolant under normal driving conditions puts the vehicle at immediate risk of severe engine overheating and sudden engine stalling or seizure while in motion. If the engine stalls unexpectedly in high-speed traffic, it strips the driver of power steering and braking assistance, drastically increasing the risk of a serious collision. General Motors is fully aware of this pervasive material defect across the Chevy Sonic model years, yet they refuse to issue a safety recall, forcing owners to operate vehicles with inherently flawed, dangerous plastic cooling components. They also refuse to help in getting the vehicle repaired or share the cost.

NHTSA ODI 11745643

1st occurence at approximately 37k miles on Vehicle has issue based on climate temperature sensor triggers a computer code 84 vehicle goes into limp mode to prevent engine failure however, this happens instantly no time to react and more than one occasion creating a hazardous driving situation in heavy traffic, vehicle also overheats creating hazardous leaks of anti freeze at boiling temperatures ability to burn anyone who comes in contact. This remains an ongoing issue with vehicle, vehicle now back in possesion of bank Santander Consumer USA, this is being reported to protect any innocent parties involved to avoid injuries or even fatality

NHTSA ODI 11576430