Thermocure and coolant temps

[hyperdub8o8]

First post! Love what you guys got going on with this forum. It has helped me out a lot! I've been a lurker for quite a long time but got a quick question. 03 4.0 auto. I just got done with a Thermocure flush and damn did it flush out a bunch of rust. I live in Hawaii and it rains a lot and is quite humid sometimes. The amount of black gunk that came out with the first couple flushes really surprised me! I was running about 215 to 220 before the flush now my temps are 195 to 210. Just redid the whole cooling system as well. Some cooler mornings and evenings my tj idles around this below 195f. Does this look normal or? I'm running a 195f thermostat. Attached is pic of the rig and a pic from my Torque app. Thanks gang!

 

[Chris]

The 4.0 is designed to run around 195 to 220 degrees, so those temps are normal.

Rust in the cooling system is caused by someone having used tap water in it. You should only ever fill a cooling system with pre-mixed coolant, or if you must use water, always use distilled water.

Oh, and welcome to the forum. It's nice that you're no longer hiding in the shadows

 

[hyperdub8o8]

The 4.0 is designed to run around 195 to 220 degrees, so those temps are normal.

Rust in the cooling system is caused by someone having used tap water in it. You should only ever fill a cooling system with pre-mixed coolant, or if you must use water, always use distilled water.

Oh, and welcome to the forum. It's nice that you're no longer hiding in the shadows

Thanks Chris! Did you happen to see the attachment of the coolant temps i'm running now at idle? 192-197 average.

 

[Chris]

Thanks Chris! Did you happen to see the attachment of the coolant temps i'm running now at idle? 192-197 average.

Yes, those temps are completely normal. Nothing to be worried about.

 

[hyperdub8o8]

Yes, those temps are completely normal. Nothing to be worried about.

Right on! Thanks again brother!

 

[Chris]

Right on! Thanks again brother!

No problem, happy to help!

 

[T_Hase89]

If you’d pay to fly me out to your place I’d be happy to give a second opinion.

 

[Jerry Bransford]

A cooling system will rust equally readily with tap water or distilled water. It's the coolant added to the water that adds the rust protection, water pump lubricant, and antifreeze characteristics. What the use of distilled water prevents is the buildup of hard water/calcium deposits inside the radiator.