Where is the cooling system thermostat located in a 2004 Chevrolet Classic?

The thermostat on a 2004 Chevrolet Classic (assuming you mean the Cavalier/Prizm) is typically located at the top of the engine, near the back of the engine block, on the passenger side. However, the exact location can vary slightly depending on the specific engine (2.2L or 2.4L).

To be absolutely certain, you should:

* Consult your owner's manual: This is the best resource for the precise location.

* Look at a repair manual or online diagrams: Search for "2004 Chevrolet Classic [engine size] thermostat location" on Google Images or a similar search engine. This will show you pictures of the engine bay and the thermostat's location.

Warning: Working on a car's cooling system involves hot coolant and potential burns. Allow the engine to cool completely before attempting any work. If you're not comfortable performing this task yourself, take your car to a qualified mechanic.