The engine was sourced through Novak with them doing a full check and refresh of accessories etc. The likelihood of a rag inside a water jacket or the like is really slim I would hope. I am open to all ideas and nothing is out the realm of possibility however.

 

You could be right about the brown Jeep radiator. I think it might be Griffin. I sold the Jeep a number of years ago and gave all receipts to the new owner.
I also have a scan tool. I will check the temps the next time I'm plowing snow which could be tomorrow.

 

I would run a 160 thermostat and try setting the fan to come on at 200.

Maybe it's true of other engine platforms but what I've noticed over the year with LS combos is once the coolant gets too hot you get to the point where it can't recover and you have to shut the car off.

 

Stopped at the tuners this morning and at first he thought tuning might help but overall the cooling system seemed ok (other than a larger radiator helping as we already know). I started the Jeep and let the fan turn on and he immediately changed his opinion. He believes the Grand Cherokee fan is moving maybe 2,000 CFM but probably closer to 1,500 per his experience (which is extensive as he does cooling upgrades on muscle cars and race cars daily). The lack of airflow in the engine compartment is more than likely causing the issues and a mechanical fan is his recommendation.

I did a quick check on the current setup and there is 7" from the center of the water pump pulley to the bottom of the current fan shroud. I can't go much lower as I have the front track bar that could cause issues space wise. Does anyone know if there are smaller fan blade options that will work on the stock fan clutch? I need to do some research obviously but if anyone has info I would appreciate it.

Thanks as always!

 

Are you absolutely sure the water pump isn't bad? I know you said you had replaced it but I had this issue with my truck a few months back. My truck has a Nelson harness with dual fans and it would only overheat if I ran it hard or WOT, I could pull over and put the truck in park and sit there and it would instantly go down, i was puzzled and after checking relays and multiple radiator flushes and thermostats it ending up being the water pump.

 

I will be doing a water pump swap as well as current one has a drip. I don't think the issue is the water pump but more the hot air stuck under the hood. Additional airflow through the radiator as well as hot air pushed out of the engine bay isn't going to hurt anything.

 

Is it dripping from that circular rear seal? I had a bad one, didn't even try to drive with it after I noticed it was weeping.

Maybe you should buy the mechanical fan / clutch / water pump assembly and see what you got. I'm interested to see how this goes, I've never messed with one of those. Sounds like it will work out.

 

I definitely agree with that, it's gotta be something simple and when you get it fixed one of those things where your mind blown that it had you puzzled so long. A new pump and better airflow definitely won't hurt that's for sure.