Where is the thermostat located on a 2003 Buick Century?

The thermostat on a 2003 Buick Century is located on the engine, typically at the bottom of the engine where the lower radiator hose connects. However, it's not readily visible without removing some components. You'll likely need to consult a repair manual specific to your 2003 Buick Century's engine (likely a 3.1L V6 or a 3.8L V6) to get the precise location and understand the removal process. The manual will show diagrams and provide the steps necessary to access and replace it.