A thermostat stuck open keeps an engine too cool; a thermostat stuck closed can make it overheat within minutes. A low temperature gauge and weak cabin heat point toward an open valve. A fast-rising gauge, steam, or boiling coolant calls...
Bad car thermostat symptoms usually include overheating, a temperature gauge that swings unexpectedly, slow engine warm-up, weak cabin heat, coolant leaks, or a P0128 check-engine code. If the gauge enters the red zone or steam rises from...
