What is the stock thermostat for 5.7 Hemi?
The stock thermostat for most 5.7-liter Hemi engines is 180°F (82°C).
In Dodge, Chrysler, Jeep, and Ram applications, the thermostat rating governs when coolant starts to flow to the radiator, affecting warm-up time, operating temperature, and overall efficiency. This article outlines the standard rating, notes possible variations by year or model, and explains how to verify the exact specification for your vehicle.
How a thermostat governs engine temperature
Modern engines use a thermostatic valve to regulate coolant flow. When the engine is cold, the valve stays mostly closed to help the engine reach its operating temperature quickly. Once the coolant reaches the rated temperature, the valve opens to allow heat to escape through the radiator. The chosen rating is a balance between fast warm-up, fuel efficiency, emissions, and long-term engine wear.
Stock temperature rating for the 5.7 Hemi
Most 5.7 Hemi installations in Dodge, Ram, Jeep, and Chrysler vehicles use a 180°F thermostat as the stock specification. This rating is common across a wide range of model years and configurations, including many Challenger, Charger, Grand Cherokee, 300, and Ram 1500 variants. Some service replacements or region-specific configurations can differ, so it’s important to verify the exact spec for your vehicle.
Model-year and variation considerations
While 180°F is the prevailing stock rating, a handful of vehicles or production runs may have variations due to emissions packages, climate considerations, or dealer-installed options. Always confirm the exact rating for your VIN to ensure compatibility with the cooling system and to avoid over- or under-heating the engine.
How to confirm the exact stock thermostat rating for your 5.7 Hemi
The following steps help you verify the correct thermostat rating for your specific vehicle. This is important because the same engine family can have small, year-to-year differences.
- Check the owner's manual or factory service manual for your exact model and year; they typically state the thermostat rating or the OEM part number.
- Use your VIN to query the official Mopar/Chrysler parts catalog or contact a dealer to confirm the exact stock thermostat designed for your VIN.
- Consult reputable parts databases or community forums with your vehicle’s year, make, and model to corroborate the stock specification and any known factory variations.
Once you’ve confirmed the rating, source the correct unit from an authorized dealer or reputable supplier to maintain factory cooling performance.
Notes on aftermarket considerations
Some owners opt for aftermarket thermostats with different ratings (for example, to alter warm-up times or operating temperature in extreme climates). If you choose to deviate from stock, ensure the rest of the cooling system (radiator, fans, coolant, and water pump) can support the altered temperature to avoid overheating or inefficient cooling.
Maintenance and replacement tips
During replacement, use a proper gasket and sealant as required, ensure all mounting surfaces are clean, and bleed the cooling system if your vehicle requires it. After installation, monitor the engine temperature to confirm the system maintains the intended operating range and that there are no leaks or airflow issues.
Summary
For most 5.7 Hemi-equipped vehicles, the stock thermostat is 180°F (82°C). However, variations can exist by model year, emissions package, or regional configuration. To avoid mismatches, verify the exact rating using your VIN, the owner's or service manual, or the official parts catalog, and replace with an OEM-equivalent unit if you’re aiming to preserve factory cooling behavior.
