South San Francisco Auto Repair

Your engine isn’t supposed to run hot—but it’s also not meant to run cold. If you’ve noticed that your temperature gauge barely moves off the bottom or your heat isn’t working as it should, your engine might not be reaching normal operating temperature. And while it may not seem like a major issue, a car that runs too cool can cause long-term problems, especially in fuel economy, emissions, and engine wear. So what causes this, and what should you do if it happens? The Thermostat Could Be Stuck Open One of the most common reasons a car runs cold is a stuck-open thermostat. The thermostat controls how much coolant flows through the engine. When the engine is cold, the thermostat stays closed to help the engine warm up quickly. Once it hits the ideal operating temperature, the thermostat opens to let coolant flow and keep the engine from overheating. But if it gets stuck open, coolant flows too soon and too freely, keeping the engine fro ... read more