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View Full Version : Thermostat change on Hemi



toxicity_27
10-24-2011, 07:12 PM
Changed out the thermostat today. Decided I'll post a little how to guide. You'll need a new thermostat, a 10mm socket, a 1/2" socket, an extension, a slotheaded screwdriver, about 1/2 gallon of the correct antifreeze, and about 20-30 minutes. Sorry about the cellphone pictures. It's all I had on me at the time.

This is the coolant you can use.
https://theultimatejeep.com/images/imported/2011/10/IMAG0121-1.jpg

First off you'll need to remove the oil filler cap so you can remove the plastic Hemi shroud. Once you've gotten that out of the way, you'll need to remove a 10mm bolt, loosen two hose clamps, and disconnect a hose to move the giant box out of the way from the front of the engine.

This is the box I'm talking about.
https://theultimatejeep.com/images/imported/2011/10/IMAG0113-1.jpg

This is the 10mm bolt and one hoseclamp on the back of the box.
https://theultimatejeep.com/images/imported/2011/10/IMAG0112-1.jpg

Here is the other hoseclamp that goes to where the air filter is.
https://theultimatejeep.com/images/imported/2011/10/IMAG0114-1.jpg

Here is the hose you'll need to disconnect.
https://theultimatejeep.com/images/imported/2011/10/IMAG0120-1.jpg

You'll need to pull the box forward to remove it as there is a small post/support that it slides onto. You can see it right below the throttle body.

Next you'll be left with this.
https://theultimatejeep.com/images/imported/2011/10/IMAG0115-1.jpg

Remove the two 1/2" bolts that connect the upper radiator hose to the engine. The back one is kind of a pain since you can't move the socket wrench too much. Make sure you have a bucket underneath the engine because coolant will start pouring out.

Once you have that removed you'll see the thermostat.
https://theultimatejeep.com/images/imported/2011/10/IMAG0116-1.jpg

Pry it out with a slot headed screwdriver. There will be more coolant pouring out.

Here's a couple of pictures of my ruined thermostat, and one comparing it to the new one.
Ruined one.
https://theultimatejeep.com/images/imported/2011/10/IMAG0117-1.jpg

The new one.
https://theultimatejeep.com/images/imported/2011/10/IMAG0118-1.jpg

Comparison between the two.
https://theultimatejeep.com/images/imported/2011/10/IMAG0119-1.jpg

Now it's time to put the new thermostat into place. Press it into the hole, it's a snug fit so make sure you get it in there. Next do everything in reverse order. Be careful not to overtighten the bolts when you connect the radiator hose back to the engine. Clear your codes and you should be good to go!

Matt
10-25-2011, 04:34 AM
before you take off the hose you want to make sure you can open the bleed port first otherwise You may not be able to properly bleed the air out of the cooling system. The bleed port is that allen screw just above the tstat.

You MUST open that up before you start refilling the system with coolant. Once coolant starts coming out of there you put it in a few more turns to slow down the flow which will help draw out any more air.

Its worth the extra $15 to get a radiator fill funnel so that you can then run the engine with the rad cap off to let the rest of the air escape.

Run the engine until the fans turn on, this means the tstat opened. Then turn the engine off, cap the radiator, make sure the reservoir is full and let it cool down.

Watch the reservoir level after the next few heat/cool cycles since it may drop a bit as any extra air works its way out.