Overheating and already replaced all the usual suspects

I bleed the system again while squeezing hoses and running up to temperature for a while using a Lisle Spill-Free Funnel (great funnel btw). I was a bit surprised to see the fluid turn a bit dark since I did a ton of back flushing prior to installing the new radiator.

I took out a quart oil and there was no water and it looked good.

It still "overheated" according to the sensor I can't trust but didn't seem to boil over.

I ordered the new oem sensor from chryslerpartsdirect.com

My plan is going to be to remove the tstat (so I can guarantee getting everywhere with the flush) and do a some more thorough back flushing, install the oem temp sensor and see what happens.

Thanks for all the help everyone
 
I've only used it once, but Prestone radiator flush fixed the problem on an old Chevy I was working on.
It dislodges LOTS of crap from the cooling system.
Try using it as directed, then flush the system out & see how it goes.
Also - I've seen the Champion 2 & 3 row radiators in multiple "Jeep overheats WTF" threads. I'm beginning to suspect they just aren't up to the task, but my suspicions have only circumstantial / anecdotal evidence backing them up so far.
 
yossarian19 said:
I've only used it once, but Prestone radiator flush fixed the problem on an old Chevy I was working on.
It dislodges LOTS of crap from the cooling system.
Try using it as directed, then flush the system out & see how it goes.
Also - I've seen the Champion 2 & 3 row radiators in multiple "Jeep overheats WTF" threads. I'm beginning to suspect they just aren't up to the task, but my suspicions have only circumstantial / anecdotal evidence backing them up so far.
Click to expand...

Notice that too, did you?

The champ 3 row I bought made my overheat problem worse.

Really puts a doubt on them.
 
CSF 3 row, on the other hand, seems to be a decent radiator.
Still, when the time comes I'll think hard on dealership vs CSF. Nothing is "cheap" if it doesn't "work"
 
Digger87xj said:
Notice that too, did you?

The champ 3 row I bought made my overheat problem worse.

Really puts a doubt on them.
Click to expand...

In general I haven't heard or read anything good about 3row radiators in general, that's why I went the 2 row champ route. Hopefully all champ radiators aren't POS, but I'll worry about that after ruling out the temp sensor.

Now all I have to do is steal the FLIR from work =) hehe J/K
 
When you get your hands on a temp gun, shoot a temp at the upper hose & at the lower hose. You want to see at least 40 degrees of temperature drop between upper hose & lower. I'm trying to find more refined numbers for you but can't. More temperature difference is better, though.
 
From what I've read a 30 degree diff is perfectly acceptable, not to contradict yoss or anything. I just thought I should add that if it comes in at 32 degrees diff, there isn't necessarily a problem.
 
I am intrigued by the recent threads where the overheat/running hot has been solved by using a factory radiator. I wish I had tried that when I was fighting a overheating 4.0. I tried every other mid-priced radiator out there, with the (oddly enough) best results coming from the cheapest radiator of any of them.
 
Digger87xj said:
I am intrigued by the recent threads where the overheat/running hot has been solved by using a factory radiator. I wish I had tried that when I was fighting a overheating 4.0. I tried every other mid-priced radiator out there, with the (oddly enough) best results coming from the cheapest radiator of any of them.
Click to expand...

My problem wasn't necessarily overheating, my radiators kept springing leaks. I punched a hole in one with a branch, replaced it with a mid price two row copper. It sprang a medium sized leak, then another and another, until I finally gave up and bought a Modine 2 row aluminum.

The Modine promptly sprung a leak, it cooled great, but sucked air during the cool down cycle and caused overheating. Repairing aluminum is doable, but it really doesn't last forever. My repair finally gave out and I bought a pig in a poke (E Bay), Taiwan radiator.

This radiator is built like a brick, the finish isn't the best, lots of odd pieces of plastic sticking out from the vacuum molding process. But it seems to cool just fine and seems pretty darned sturdy. Time will tell how well it is going to last.

I think many of these hard to find overheating problems may be tiny leaks up high, where they suck air during the cool down cycle. That was my last overheating problem.

Between tiny leaks springing up in my old plumbing rubber and the heater valve and the radiator itself, the probability of a tiny leak that sucks air during the cool down cycle is pretty high, coolant is around 800 times thicker than air. During a normal cool down cycle the system sucks coolant up at least foot out of the coolant recovery bottle, there is a substantial vacuum in the system. Some of those coolant leaks evaporate before they ever leave a stain on the ground and may be hard to spot. Less likely to be an issue on leaks low in the system, but high leaks are likely to suck some substantial air in.
 
child9 said:
From what I've read a 30 degree diff is perfectly acceptable, not to contradict yoss or anything. I just thought I should add that if it comes in at 32 degrees diff, there isn't necessarily a problem.
Click to expand...

Curiosity, where did you read it? I don't disagree, I just couldn't remember where I'd gotten the 40 degree thing. Tried to find something in text, couldn't.
 
yossarian19 said:
Curiosity, where did you read it? I don't disagree, I just couldn't remember where I'd gotten the 40 degree thing. Tried to find something in text, couldn't.
Click to expand...

A lot of variables with temperature drop, ambient temperature, humidity, air flow volume, even the temperature going in.
 
8 mud is right too. I recall googling what an accepted temperature drop across the radiator is when my dad was having cooling issues with his car and ppl were trying to determine if it was flowing or blocked w/o a flow meter being put on it.

I believe I found the article. I can't speak for the man's credentials and I did not read it in it's entirety...but it is written in such a way and contains lots of other information that coalesces with what I understand so I buy it for the most part. The excerpt in question and about 1/4 of the way down the page reads "When the inlet temperature is generally around 190°F and the return outlet temperature is 165-175°F or lower, depending upon ambient air temperatures, then we can pretty much agree that the rig is operating per the design parameters that were set by the good folks at AMC at the beginning of the odyssey."

Full page here: http://oljeep.com/rad/edge_radiator.html
 
Worked for an OEM radiator company for years. Details do make a difference. Even the angle of the little windows in the fins is critical to throwing off heat. We verified that with a special testing machine daily. Some aftermarket companies might not do that.
 
Capacity is 3 gallons. I think a lot of overheating is due to low coolant. I know I can only get 2.5 gallons in mine...overflow included... I'm going to try and keep adding coolant until I can get 3 gallons in there...but I don't have an overheating issue.
 
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