should be above...is that it below where the old canister used to be???...I am on my phone so cant see very well...that lower hose will collapse under load without a spring...you may not see it while parked and giving it gas but under load they due collapse if they are weak and dont have a spring...you have done everything else so I would think that may be the culprit...that and you cant burp your system well with the overflow lower then the fill neck at the radiator

 

Well I had the same problem with mine and I did that. You can see it collapse, unless that was my imagination. A load on the engine has nothing to do with how well the water pump cycles coolant. Blockage or leaks is what causes over heating. Not all lower radiator hoses for the 4.0. have springs it depends on the brand you buy.


This is how you should install your thermostat
https://w05.dealerconnect.chrysler.c...S/800cede5.gif

 

Thermostat is correctly installed.

 

Hmm....

Do make sure that your serpentine belt tension is correctly adjusted.
If the belt tension is not right to specifications, the water pump will circulate water at much slower rate--> which can cause overheating.

 

I hate to tell you this, but I think you have a bad head.

 

You said it was at high speeds (maybe high RPMs) which makes me think of the oil type or level. Maybe you could try running a full synthetic oil.

 

Won't make any difference.

 

I am using 60% Lucas oil and the other 40% is a high mileage quaker state. Oil level is good. My motor when first started up makes a scratching sound coming from the middle of the motor which makes me think that I have bad rings on one of my cylinders. And maybe my oil pump is clogged. I keep hearing of this sea foam stuff what is it and will it work to unclog junk in the oil pump? How does it work?

 

That's not going to solve the overheating problem.

 

Holy crap out mean 60% Lucas oil additive! Wowowow what do do you have 70psi? That's a lot of thick crap. My 90 I run 5-30. That's it. Hat engine wasn't made to run that judo of oil... that's killing it on start up! A god synhetics and some seafood will clean it. I would try 5-30 don't worry about he additive.

 

Yeah maybe you need to change your oil and filter to a good 10W-30 oil and a Wix filter.

That scratching sound may be lack of lubrication on startup due to too thick of oil.

But that won't solve the overheating problem.

 

It might actually.. I don't know how thin that oil gets at temp by with that much he could have A LOT of extra friction. Friction=lots of extra heat+wear=failure!!!!!

 

His main problem is still overheating.

I had the same problem before AND after a quality rebuild. Had to tear down, get another head and have it rebuilt.

No more running hot after that.

 

1. Make sure your lower rad hose has a massive spring in it.
2. If that don't help, then reflush the block with some prestone super flush to try and remove as much crap as possible and possibly remove any passage blockages.

Btw, I kind of like the idea that maybe the gauge is wrong or the temp sending unit is faulty.

 

Oh, hey, I just read the second page. Try NOT running the equivalent of 60 weight oil in your crankcase. Lucas oil stabilizer is an 80W gear oil. Stop using it entirely. Use a full synthetic oil; like Mobil 1, valvoline, or pennz ultra and buy a good Bosch, wix, Mobil 1, or Purolator oil filter.