6.1L thermostat swap *

[bmartin9122]

Okay guys... Thanks goes out to Meister for his excellent thermostat thread, which finally prompted me to dive into this simple mod. BTW, I am assuming this would also work just the same on the 5.7L motor. I took my time spending only about 30-45 minutes, since I am a spaz when it comes to wrenching.

Wait for the engine to cool before starting!!!!

1. Here is the Robert-Shaw 170 degree thermostat packaging. I picked up the t-stat at Autozone (part #383170) for $9.99 plus tax.


2. Park your LX with the front of the car higher than the rear as much as possible. This will limit the quantity of coolant that wants to escape.

3. Spread some rags over the radiator area, and grab a 1/2" socket with an extension.


4. With firm pressure, carefully remove the top bolt and set it aside. At this point, red coolant may start to leak out, but it shouldn't be significant.


5. Here is where you really need 3 hands. While holding a 1-gal freezer bag underneath, begin loosening the lower bolt SLOWLY. Coolant will begin to flow out of the upper radiator hose. Be patient and collect as much coolant as possible.
edit: HEMIWAGN has successfully duct taped the freezer bag to various engine components instead of holding the bag. Great idea!!!

[bmartin9122]

6. You will get about this much out of the hose.


7. Push the hose to the side to expose the thermostat. You will also see the obvious rubber gasket seal. Many thermostats do not come with a replacement gasket, so you will need to salvage the original.


8. Now you need a medium to large flat screwdriver to CAREFULLY pry the old thermostat out of the housing. This is another 3-handed endeavor as you will need to pry the thermostat while holding your plastic bag. A LOT more coolant will escape as you extract the old thermostat. Wait until the coolant stops flowing before pulling the thermostat completely out. If you put your LX on an incline facing the wrong way, then you will drain almost the entire reservoir. I know this from a recent experience.


9. Here is the old and new thermostat side-by-side. Notice the length difference. I'm not sure if this is important, since the difference is so small.




10. Here is the new Robert-Shaw thermostat right before installation. Notice, the salvaged red gasket has already been transferred to the new thermostat. Start from the bottom, and as you reach the top, carefully tuck the red gasket into the housing with a tiny flat screwdriver. Make sure the brass dogbone valve is oriented to the top.



11. The reinstalled new themostat. Note the position of the brass dogbone valve.


12. Reconnect the upper radiator hose and snug the bolts.

13. Pour the recovered radiator coolant back into the overflow reservoir, and you're done!


Here are some pics of my Mag after fully warming up. Despite the high ambient air temperature, the engine remains a relatively cool 185 degrees!

[2005MagnumRT]

Hey guys I have a 2005 Magnum RT 5.7 HEMI. I have programmed my ECU with the Hypertech Power Programmer III. If I put 180 degree thermostat will the fans turn on earlier than to keep the water in the radiator at 180? what tells the fans to turn on the ECU? thanks

[2005MagnumRT]

Hey guys I have a 2005 Magnum RT 5.7 HEMI. I have programmed my ECU with the Hypertech Power Programmer III. If I put 180 degree thermostat will the fans turn on earlier than to keep the water in the radiator at 180? what tells the fans to turn on the ECU? thanks

nevermind, I see that i will need a fan mod

[mullens]

nevermind, I see that i will need a fan mod

Hey Mike I see you live in Vegas also. Make sure you get one of the high flow thermostats like the MotoRad or the one illustrated in the demonstration. You can tell by how large the opening is. The stocker is also a good example of high flow. Normal thermos will get us by in the winter, but when summer hits I'd want the extra coolant.