How to Change a Dodge HEMI Thermostatby Gregory Crews
The Dodge "Hemi" is short for the Hemispheric engine that Dodge uses on its high-performance vehicles and select trucks. The thermostat in the "Hemi" regulates the engine temperature and opens to release coolant in to the engine. Once the engine cools down, the thermostat will close. A faulty thermostat will prevent the engine from receiving the coolant. This can cause the engine to overheat. Replacing the thermostat can be done in a matter of minutes.
Open the hood for access to the engine compartment. Locate the thermostat housing at the end of the top radiator hose.
Use a socket wrench to loosen the two bolts at the thermostat housing. Place a sealable bag under the bottom of the housing to collect the coolant as it pours out of the opening.
Pull the hose and the pipe away from the thermostat housing. Place the bag under the housing to catch any excess coolant. Pry the thermostat out of the housing with a flat tip screwdriver. Some coolant will flow out. Catch all the coolant coming out with the bag.
Pull the gasket off from around the edges of the old thermostat. Place it around the new one. Push the new thermostat in the housing. Ensure the spring end goes in first.
Use a socket wrench to tighten the hose and pipe back on to the thermostat housing. Ensure the bolts are tight to create a seal so coolant does not leak out.
Twist the radiator cap counterclockwise to remove it and pour the coolant back in to the radiator. Start the car and allow it to warm up. Once the car is warm, the level of the coolant may drop. If so, pour in additional coolant. Consult the owner's manual or the Dodge dealer for the correct type of coolant.
Tighten the radiator cap back on by hand. Close the hood and turn the car off.
- Automedia: Thermostat Replacement
- "Chrysler 300 (2005 thru 2009), Dodge Charger (2006 thru 2009) and Magnum (2005 thru 2008) Haynes Repair Manual " John Haynes; 2008
- Purchase a thermostat at any Dodge dealer or automotive parts store.
- Inspect the gasket on the thermostat to ensure it is not torn or broken. If the gasket is broken, replace it immediately.
Things You'll Need
- Socket wrench
- Socket set
- Sealable bag
- Flat tip screwdriver
- 1 gallon coolant
- Use caution working around coolant, as a hot engine can cause burns. The coolant system is also under pressure; ensure the car has been sitting for at least an hour so the engine and coolant can cool down and depressurize.
Gregory Crews has been in the film industry for three years and has appeared in more than 38 major motion pictures and 16 television shows. He also writes detailed automotive tutorials. His expertise in the automotive industry has given him the skills to write detailed technical instructional articles.