I just installed a new NAPA 191 180 degree thermostat and the JGC appears to be running hotter. I only drove it around the block and the temp went as high as 225 and never went below 215. Any suggestion? Do you have to disconnect the battery to reset?

same thing happened to me after I put in a 195.


you might have not replaced the coolant that came out when you pulled the hose.

Try adding coolant and see if that works

Did adding the coolant help? I was able to capture the coolant in a bucket and have since measured - only comes out to about 2 1/2 cups.

Just drove it down the freeway for a couple of miles and the temp went to 230 and dropped to just below 225. I was better off with the stock thermostat.

I've never messed with the cooling system on this vehicle, but on my others, I've always had to bleed the air out of the system after opening up the system like that for a thermostat.

Alex

I've never messed with the cooling system on this vehicle, but on my others, I've always had to bleed the air out of the system after opening up the system like that for a thermostat.

Alex
Agreed. Air in the system can make the car run hotter.

Agreed. Air in the system can make the car run hotter.

Air pockets in the system can make you over heat.

How do you bleed air out of the cooling system? I have never done this on my other cars.

How do you bleed air out of the cooling system? I have never done this on my other cars.

On my BMWs there's a bleeder screw that you loosen while running the engine. After you clear the air, you'll start to see coolant. Then you just tighten back up. Dunno about these new fangled hemi things. :D

Alex

How do you bleed air out of the cooling system? I have never done this on my other cars.

Take your radiator cap off (**Do this with the car off and cool. Opening the cap on a hot car can be dangerous because the hot coolant will be pressurized.**) and let your car idle until it reaches operating temperature (running the heater during this time can help). Then, try squeezing your upper radiator hose to see if there is any air present. If you can squeeze the hose, then one of two things is possible. Either your car has not reached operating temperature yet and your thermostat has not opened or you have air in the system. Squeezing the hose can force the air into the radiator which will burp out the through the open fill neck. Continue to do this until you feel you have all the air out (the hose should get hard). You will obviously need to add some coolant after this because the space the air used to occupy has now been filled with coolant leaving the amount of coolant left in the radiator less than before.

Thanks for the tip. I will try later tonight and hopefully this will help. For those of you who have changed the thermostat did ya'll have to do this as well?

Reinstalled the foactory thermostat and filled with coolant. Everything is working as original. I still would like to install a different thermostat-perhaps a different one from the NAPA 191. In order to get any benefit from using a different thermostat do I need to do the fan mod?

There should be no need to bleed it.......that is what the overflow tank does. In addition when you removed the thermostat housing I will guarantee you that you lost WAY MORE than a couple of cups!

You should have removed the radiator cap and filled the radiator directly, started it..... added more and closed the cap. As the coolant reaches temp it expands and "burps" back into the overflow as it cools the vacuum will draw the needed coolant from the overflow tank. The correct level is then adjusted at the overflow after a cycle or two.

did the 180 a week ago.

while driving it will hover near the 185 marker, but while at a stand still it will go back to 215 at which point the fan automatically kicks.

My coolant tank is full of coolant.

I had some spraying of coolant after which I replaced the radiator cap. No more spraying from what I can see but she still runs hot. Any ideas.