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Tranny cooler woes

I had the Hayden stacked plate(largest one they make, 30,000GVWR?) in front of the condenser on the passenger side. My engine ran hot with that set-up, the tranny ran warm but tolerable. Now my engine runs cool but the tranny runs hot. I will look it over this weekend and move what needs to be moved to make it work. I really doubt my new low mileage tranny is a issue.
 
Maybe you should do the trick lots of ppl make, put a switch on the e-fan. That if you don't have a custom e-fan setup similar with DB Offroad... Also, regarding the engine heat, I end up cutting the hood and installed some cheap turbo plastic scoops from eBay, that fixed the heating issue I had in the summer. And one more thing, I realized that in the summer, keeping the winch cover causes the engine to overheat a bit, taking it out fixed the issue. My winch is over the bumper, so it cuts out some air that goes in the radiator, and that cover doesn't help at all. On Highway, I was running with e-fans all the time. Just trying to give you some extra ideas, I hope you'll fix it eventually and enjoy your rig! Oh, and btw, 30,000 gvw cooler is what I have also, it's more than enough if you don't tow the house after your jeep...
 
Its still over-heating. I have now replaced the TCU/Transmission/torque converter/tranny lines/New cooler with a fan on it/new temp gauge/new sending unit.

It runs 300 even on a 40* day.

I give up.
 
Did you bypass the tranny cooler in the radiator? I can't tell from what I read, but if you did, try putting that cooler in the loop also.
 
IH392 said:
Did you bypass the tranny cooler in the radiator? I can't tell from what I read, but if you did, try putting that cooler in the loop also.
Click to expand...

Yes, in fact, I have a 3 row brass radiator with no tranny line bungs in it.

I'm not sure what my next step to fix this will be.
 
Shorty said:
what does the IR pyrometer tell you the temps are? I can't believe you've got anything wrong other than a gauge problem,
Click to expand...

IR is giving me lower temps than the gauge(s) but I don't overly trust these cheap IR's. In general I get 60-80* less with the IR aimed at the cooler lines going into and out of the tranny. I have senders on each line going to a SPDT toggle then to the switch, I can flip it from one sender to the other
 
IH392 said:
What does the IR thermometer read when you point at the thermostat? Same as the coolant temp on the dash?
Click to expand...

Not always, that's why I do not trust it. It seems to read funny the brighter the object and or material its made from.

My next step is borrow another IR and see what temps I get from using a different one.
 
xjtrailrider said:
My next step is borrow another IR and see what temps I get from using a different one.
Click to expand...

methinks that is a good plan-- I can't see your temps rising as quickly as they do and staying where they are with two separate transmissions. especially since they continue to shift normally and the fluid doesn't burn.
 
Shorty said:
methinks that is a good plan-- I can't see your temps rising as quickly as they do and staying where they are with two separate transmissions. especially since they continue to shift normally and the fluid doesn't burn.
Click to expand...

Yea! What Shorty said.

There is this one item that is not quite right. Is it possible to get a manual temperature gage to compare the readings? I doubt the AW4 is the problem,...well maybe it is also but I doubt that.
 
I still think it's a resistance issue, if you have that switch for the 2 probes and one gauge, that can modify the resistance. The b&m gauge you and I have, comes with a thin wire, about 6-8 ft. I think you should double check deleting the switch and using a thin gauge wire of that approximate length, if the ir thermometer won't work this time.
 
Prom3theus said:
I still think it's a resistance issue, if you have that switch for the 2 probes and one gauge, that can modify the resistance. The b&m gauge you and I have, comes with a thin wire, about 6-8 ft. I think you should double check deleting the switch and using a thin gauge wire of that approximate length, if the ir thermometer won't work this time.
Click to expand...

You may be on to something there! One sender is wired to a small thin wire while the other is on a 16ga. That is to the cowl, then to the switch and back up to the gauge its all 16ga.

I hope to have time to test drive it tomorrow.
 
*AGGRAVATED*!

I installed a "known" good B&M gauge on Thursday and drove to work this am. It ran cool, 120 or so in 40* weather. Today on the way home it hovered around 150 in 60* weather. i stopped at oriellys to pick up parts for a 4.0 I'm building and when i get in the jeep and start it up the gauge jumps to the red! 300*! Not maxed out, just to the red.

The Jeep runs fine/shifts fine, no issues

So i pulled over and got out both IR's.

At the tranny pan I get 150-160, both guns
At the lines I get 145-155 both guns/both lines
At the cooler I get 100-120 at the inlets/outlets with both guns.

I do not think its over heating. The gauge circuit seems to be the culprit. But why?

I have 16ga going from the outlet side of the tranny sender to the switch, I have 18ga going from the inlet side of the tranny sender to the switch, I have 16ga going from the center pole of the switch to the gauge. The gauge and senders have solid grounds and the gauge is wired off of the acc side of my auxiliary fuse box.

All of the sender wires under the hood are in a loom and protected all the way from the cowl to the senders. Nothing is shorted or grounded. I don't get it?
 
Last edited:
Prom3theus said:
I still think it's a resistance issue, if you have that switch for the 2 probes and one gauge, that can modify the resistance. The b&m gauge you and I have, comes with a thin wire, about 6-8 ft. I think you should double check deleting the switch and using a thin gauge wire of that approximate length, if the ir thermometer won't work this time.
Click to expand...


I am with Prom3theus on the issue of resistance. The wire size and length should not be an issue,...I would not think so. However, I still think :--

1) The gage and the sender/s are not compatible.
2) The wiring is not correct.
3) There is a grounding issue at the gage.
4) The switch (to switch between the two sending units) is bad.
5) The sending units themselves need to be grounded properly.

It is good to hear that the AW4 is good just the messenger is misrepresenting the truth.

I too have two senders, one gage and a switch to switch between the senders. While it appears the reading is accurate (enough) they are slow to respond when switched i:e the will linger about 20 degrees lower and come up to the actual temperature after a couple of minutes. Mostly, I just leave the switch to display the temperature coming out of the AW4.
 
Did you swap out the sending unit with the gauge?

Are the sending units single wire? If so, how are they grounded? The senders must be grounded and single wire ones typically ground to the fitting. T-ing into the hardline is not a good enough ground. If that is how it is installed I would recommend finding a two wire sending unit, the other wire will be ground. However, typically the more resistance, the cooler the gauge will show.

Can you provide a pic of your sending units?
 
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