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Discussion Starter · #1 ·
I was wheeling in the mountains east of San Diego and all of a sudden a warning I'd never seen before, "HOT OIL," began flashing and ringing loudly on my dash. I wasn't doing anything usual or especially challenging, just climbing a rough jeep road that was hardly beyond beginner. My crankcase showed the oil temp was fine, and I looked under the hood and everything was normal. It was only after consulting WF that I learned the "oil" was the transmission fluid, not the crankcase oil. [Another brilliant move by Jeep/Chrysler.] Also that the situation is very serious.

So my question is -- was the fluid damaged or degraded for even the 30-60 seconds while it was too hot? Should I flush the transmission fluid system and replace it with fresh fluid? Is there anything else I should consider doing? Again, I stopped as quickly as I could when the alarm began ringing but it did take another 30 seconds of driving to get to a flat place out of the way of the other vehicles?

Thanks for any advice.

P.S.: For now at least, don't ask me to call the dealer service shop. I called them before doing my homework on WF and the clown said he'd never heard of the HOT OIL light and, if the warning went away, everything was probably just fine anyway. [He won't be working there after his General Manager receives the letter I'm going to write.]
 

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I have seen that pop up from time to time, usually it is because people are driving around in 4H when they should be in 4L.
 

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Your Jeep is/will be fine.. Next time, use 4L when going up those hills/tough spots..
WHY on earth the geniuses decided to make it say HOT OIL instead of HOT TRANS is beyond me..
 

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I was wheeling in the mountains east of San Diego and all of a sudden a warning I'd never seen before, "HOT OIL," began flashing and ringing loudly on my dash. I wasn't doing anything usual or especially challenging, just climbing a rough jeep road that was hardly beyond beginner. My crankcase showed the oil temp was fine, and I looked under the hood and everything was normal. It was only after consulting WF that I learned the "oil" was the transmission fluid, not the crankcase oil. [Another brilliant move by Jeep/Chrysler.] Also that the situation is very serious. So my question is -- was the fluid damaged or degraded for even the 30-60 seconds while it was too hot? Should I flush the transmission fluid system and replace it with fresh fluid? Is there anything else I should consider doing? Again, I stopped as quickly as I could when the alarm began ringing but it did take another 30 seconds of driving to get to a flat place out of the way of the other vehicles? Thanks for any advice. P.S.: For now at least, don't ask me to call the dealer service shop. I called them before doing my homework on WF and the clown said he'd never heard of the HOT OIL light and, if the warning went away, everything was probably just fine anyway. [He won't be working there after his General Manager receives the letter I'm going to write.]
3.8L JK automatics have woefully inadequate transmission cooling capacity. The cooler is at the bottom of the A/C condenser, behind the front bumper. You've experienced the common symptom, but taken to tremendous the fluid can overheat, expand, runout the fill tube and pour onto the passenger side exhaust manifold. At that point it ignites and can set the entire rig on fire. Many cases have been documented.

The simple fix is to install an auxiliary trans cooler. There are several dedicated kits on the market, but even a parts store it will get the job done. Even Mopar has a kit, sold as a "towing" accessory. Whatever, get one installed ASAP.
 

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Discussion Starter · #5 ·
3.8L JK automatics have woefully inadequate transmission cooling capacity. The cooler is at the bottom of the A/C condenser, behind the front bumper. You've experienced the common symptom, but taken to tremendous the fluid can overheat, expand, runout the fill tube and pour onto the passenger side exhaust manifold. At that point it ignites and can set the entire rig on fire. Many cases have been documented.

The simple fix is to install an auxiliary trans cooler. There are several dedicated kits on the market, but even a parts store it will get the job done. Even Mopar has a kit, sold as a "towing" accessory. Whatever, get one installed ASAP.
Nice answer. Do you have a recommended cooler? Or should I just get the ones on Amazon?

Also, do I need to flush the tranny fluid or just leave it be?
 

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Check the color of the fluid. Red fluid is good. Dark fluid is bad and will smell burned.
 

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YES

Add the B&M 70268 SuperCooler Automatic Transmission Cooler

Mount towards the right side of the radiator and run the hoses under the front and splice in as directed in posts about this. The hose length will be just right. This is easy peazy with basic hand tools. I added a temp controller fan to mine, but the cooler should be fine by itself. You won't see that warning again.

If you need help or more info let me know.
 

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Nice answer. Do you have a recommended cooler? Or should I just get the ones on Amazon? Also, do I need to flush the tranny fluid or just leave it be?
I have the Mopar cooler, which mounts and is plumbed as if it was OEM. Kind of pricey. Mishimoto and ORW have excellent dedicated kits as well. However the B&M kit noted is just as good for adding cooling capacity.

You'd only have to change the fluid if it looks and smells burned. Chrysler uses ATF+4, which is a pinkish red. It stinks a bit like burned fluid. My hunch is yours is OK, but if the rig is near the recommended 60k mile change point might as well change it and the fluid at the same time.
 

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If it was my Wrangler, I would have the trans oil and filter changed. Having it serviced is cheap insurance, verses a transmission rebuild!!!

I would also definitely have a external cooler added. The B&M SuperCooler, has a excellent reputation...
 

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My tranny measured 297 degrees on my thermal imager at the snow line at 39 degree outside temp while driving at around 10mph. This also happened to me in the summer time with long climbs up logging roads. Even after more than once, my oil did not look burned or discolored at all, it still looks new.

When I added the cooler, I did let it warm up then top off with a bit more fluid. I captured the fluid in a box with some newspaper when I cut the lines and I swear it was not even a cup of leakage.

For the price and labor, don't put this off, just get it done and never have to worry again.


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