Scion tC temperature gauge fluctuating between hot and cold on Scion tC

Some Scion tC owners report experiencing fluctuations in the temperature gauge between hot and cold, which may be caused by several factors. These issues could stem from a bad thermostat or insufficient coolant in the system. Additionally, trapped air in the cooling system can lead to erratic gauge readings. A defective coolant temperature sensor or a faulty temperature gauge might also contribute to this problem. Owners are advised to check for leaks in the cooling system, as these could exacerbate the situation. Observing the vehicle while idling and reaching operating temperature can assist in diagnosing the issue by revealing smoke, coolant leaks, or unusual smells. It is crucial to address these potential problems to prevent further complications with the vehicle's cooling system and engine health.