Where is thermostat on 2006 Chevy Express van?

On a 2006 Chevy Express van, the thermostat is located in the engine compartment, typically near the engine block where the upper radiator hose connects to the engine. To access it, you may need to remove the upper radiator hose and the thermostat housing, which is usually secured with bolts. It's important to ensure the engine is cool before attempting to check or replace the thermostat.