Coolant Temp Increasing at Highway Speeds

Bowhunter said:
Thanks for taking the time to break that down, I appreciate it!

If I use thermocure, I would think I’d have to drain the block before putting in the new coolant because if not then I have a gallon of liquid in the block with some thermocure that would stay in the cooling system and I don’t think I should keep the thermocure in long term.

I ordered that tool. Local auto parts store doesn’t carry the thermocure. Any other decent cleaning products or is that really the only one worth using?
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All good man, happy to share info. Do whatever makes the most sense for you.

Regarding concerns about getting it all out, you will know it's out because it won't be discolored anymore (or smell). Might take a bunch of flushes though if you don't drain the block.

Life is much easier once you get the plug out (best of luck if you go that route).

I haven't used other products, but I've seen evapo-rust available at auto stores. Thermocure has the same evapo-rust labeling on its label but I don't know how they differ. I only paid $17 for Thermocure on Amazon in 2021, but it's double that price now. For that reason, I'd probably look into evapo-rust and check on local stores. There might be alternative products out there that I'm simply not aware of.

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I did this last summer in Texas.

I learned this:
1 add the Thermocure and drive around a day ish.

2. Drain the radiator and block and take out the thermostat.

3. Put the housing back with no thermostat so it all flows.

4 . Start and run 3-4 minutes.

5. Drain radiator and block.

Repeat until it’s clear

6 Put in a 195 Mopar thermosat.

7. Fill Zerex and distilled 50/50

This is my thread below last summer when i learned this on here. If you don’t pull the thermostat, you have to get it to 195 to move the whole system. Taking it out, it’s all moving and you don’t have to get it hit, let it cool, and take 4 dam days to do this.

Learned that here from Blaine.


https://wranglertjforum.com/threads/2005-tj-cooling-system-parts-change-in-texas.63302/
 
cpwolf said:
I did this last summer in Texas.

I learned this:
1 add the Thermocure and drive around a day ish.

2. Drain the radiator and block and take out the thermostat.

3. Put the housing back with no thermostat so it all flows.

4 . Start and run 3-4 minutes.

5. Drain radiator and block.

Repeat until it’s clear

6 Put in a 195 Mopar thermosat.

7. Fill Zerex and distilled 50/50

This is my thread below last summer when i learned this on here. If you don’t pull the thermostat, you have to get it to 195 to move the whole system. Taking it out, it’s all moving and you don’t have to get it hit, let it cool, and take 4 dam days to do this.

Learned that here from Blaine.


https://wranglertjforum.com/threads/2005-tj-cooling-system-parts-change-in-texas.63302/
Click to expand...

Thanks!

Any tricks to keep the block drain hole from spraying coolant everywhere? Trying to keep the coolant dripping everywhere because I have a small dog
 
Dumb question…

After I run the thermocure through and drain the block, how do I get coolant back into the block?

My OCD is in left field and thinks that the block will cook while I’m idling in my garage for 10 or so minutes trying to get the coolant up to 195 so that the thermostat will open up and allow coolant into the empty block
 
Bowhunter said:
Dumb question…

After I run the thermocure through and drain the block, how do I get coolant back into the block?

My OCD is in left field and thinks that the block will cook while I’m idling in my garage for 10 or so minutes trying to get the coolant up to 195 so that the thermostat will open up and allow coolant into the empty block
Click to expand...

Liquid passes through the block after the water pump. Simply fill up the radiator (repeatedly) to fill the coolant system.
 
Bowhunter said:
Thanks!

Any tricks to keep the block drain hole from spraying coolant everywhere? Trying to keep the coolant dripping everywhere because I have a small dog
Click to expand...

I have a decent size tub that was under it. Cheap clear one from wal mart. Wasn’t an issue, I have 2 dogs, but there wasn’t anything on the ground thag I didn’t hit easy with a shop towel.
 
Try putting a cup of water soluble oil in it.

It is Surfactant and causes the coolant to transfer more heat from the engine.

I have been use water soluble oil for decades it works.
 
Any tricks to keep the block drain hole from spraying coolant everywhere? Trying to keep the coolant dripping everywhere because I have a small dog
Click to expand...
Just hose down the driveway. Coolant is poisonous but also biodegradable
 
Update: I’m in the middle of the flush process where I let the blue devil stay in the system while I drive for a few days.

So I drained the system, with distilled water, several times last night per the directions and then added the flush and fill with distilled. I burped the system and got a fair amount of bubbles out. Then at 9pm took it for a 5 mile city drive. All temps looked good so I parked it and 1030am today I when to open the rad cap to see if it need any more water before taking it for another drive. After 12+ hours there was still a fair amount of pressure In the system when I opened the rad cap even tho it was cool.

Rad cap was a new 18psi stant that hadn’t done this in the past. Put a new motorad 18psi rad cap to see if the stant was damaged. Was going to take it for another drive but wanted to post here to see if anyone has an idea why it would hold pressure that long with the distilled water and blue devil in the system?
 
Another update:
After driving it 15 miles on the hwy today and letting it sit and cool for 7 hours, still a lot of pressure in the system when I opened the radiator. Line to overflow is clear. This time I tried a new motorad 18 psi rad cap.

I don’t remember there being pressure in the system when it was cold and full of coolant. Oil looks to be normal and it’s just clear distilled water in the radiator. Fingers crossed it’s not a head gasket leak.

Anyone know if having full distilled water with blue devil rad flush in the oolong system would create this long lasting pressure in the cooling system?
 
Hello All,

Wanted to follow up to provide my findings in case it helps anyone.

After noticing the heater on would greatly reduce coolant temps (essentially an aux coolant cooler), I bought a new mopar rad.

And I think that was it! The original rad had a lot of leaves (pic attached) that looks to have been blocking air flow. Leaves were not visible until removing radiator.

30 miles on the highway (85-88 ambient temp), the coolant temp ranged from 194-199! Same run used to range from 212-225. My existing t stat is likely a little worn and slow to react to change in temps so down the road I will replace it with a more precise (new) t stat that will put the temp likely between 200-210.

Thanks to all that helped me along this temp issue!

70624202098__E355633F-01B3-4153-B4F5-60CEAF64EB2A.jpeg
 
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