• ACDelco Professional Engine Coolant Thermostats Primary Image


  • Control the flow of coolant through the radiator to enable the engine to reach and maintain its normal operating temperature
  • Professional, premium aftermarket replacement engine coolant thermostat
  • Provides the performance and dependability you expect from ACDelco
  • Manufactured to meet expectations for fit, form, and function


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ACDelco Thermostats And Caps

An ACDelco Professional, premium aftermarket Engine Coolant Thermostat is a temperature controlled valve located in the engine coolant outlet to, or the inlet from, the radiator, and is the ideal high quality replacement for your GM vehicle. It controls the flow of coolant through the radiator to enable the engine to reach and maintain its normal operating temperature. These premium aftermarket replacement components are manufactured to meet your expectations for fit, form, and function.


24 Month/Unlimited Mile Limited Warranty*: Our most common Parts Warranty offers coverage on the majority of our Genuine GM Parts and ACDelco service replacement parts. Effective on parts purchased April 1, 2018 and later to the original retail purchaser. Contact seller for limited warranty part details, qualifications, and possible labor coverage.

Learn more about ACDelco warranties:


Could a damaged thermostat affect engine performance?
Yes, a broken thermostat could cause the engine to overheat and lead to engine damage.

Is there a way to verify that my vehicle’s thermostat is functioning properly?

Yes, the thermostat can be tested by boiling it in plain water for approximately 3-5 minutes. If the thermostat does not open, it should be replaced.

Could a damaged thermostat affect interior heat?

Yes, the thermostat can become stuck in the open position. This will prevent the engine from reaching operating temperature in cold weather, resulting in poor interior heater performance.


Maintain proper coolant levels and check level monthly (Note: Never attempt to remove a radiator cap while the engine is hot. Serious injury could result).

• Replace coolant with a mixture of antifreeze and water according to the vehicle manufacturer's recommendations.
• Inspect engine belts for cracks or missing sections; check belt tension.
• Evaluate radiator and radiator cap for leaks, corrosion, or a worn cap gasket.
• Examine hoses every 12 months. Look for leaks, cracks or rot. Replace hoses showing signs of wear.
• Tighten any loose clamps. Always replace clamps when replacing hoses.
• Have cooling system inspected immediately if instrument panel-mounted temperature gauge indicates engine overheating.
• Periodically, remove bugs, leaves and other debris from the front of the radiator. They can block airflow and substantially reduce cooling efficiency.




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