I've searched the board for "hot oil" and couldn't find anything, hence my post.

I have a 2011 JKU, 3.5" lift, 35" tires and the stock 3.8L engine with auto trans. No other mods. Over the years I have gotten this "hot oil" warning when driving up a hill, even a mildly steep hill, during cool or warm weather. If I understand it right, the warning is about the transmission fluid getting too hot? Whenever this occurs, I usually come to a stop to let things cool off, then drive on my way.

The transmission fluid is not low, and does not need changing. I'd be grateful for anyones thoughts or help understanding what might be causing this warning to come on.

Thanks much,
Shawn

PS. I Googled hot oil and jeep and got a whole different result if you know what I mean.

 

You should look into an aftermarket transmission oil cooler. Others can correct me if I'm wrong, but this is relatively common in pre-2012. Starting with the 2012 model year, the trans oil cooler is standard.

 

Thanks Rob for the reply; I'll check it out.

 

the problem is that the torque converter only locks up in 3rd, so when driving slowly, uphill, in 2hi or 4hi (or 4lo in 4th) the trans oil overheats. to avoid, drive in 4lo with overdrive turned off. this will force the torque converter to lock up causing less heat and better cooling. Trans cooler may or may not help in this scenario.

EDIT:
Yes, absolutely correct, I should not have assumed it was dirt and slow speeds.
Also, way back when, Jeep had a service bulletin related to this and did a software change to "fix" the issue (really just set the sensor to a higher temp and kicked the high speed fans on earlier). Might want to see if that has been done.

 

Maybe I interpreted it wrong, But when the OP is saying he's driving up a hill, I take that to mean an incline on a highway, not a dirt hill off-road. If that's the case, you don't want to be in 4WD. In this scenario, an auxiliary trans cooler should fix the issue.
Years ago I remember good threads about the hot oil topic, which I think was more related to driving in sand. The pre-2012 would get that warning while driving in 4-hi on soft sand if you didn't have an auxiliary cooler. Running in 4-lo would be a better option to avoid the warning.

 

There are tranny coolers with integral fans built in. DeRale is one brand I know of.

 

I have the 3.8 and got that light going out to vegas once on the freeway back in 2009. I installed the Mopar aftermarket transmission cooler and never saw it again. I did just post about burnt transmission fluid about 15 minutes ago in another post lol so take it for what its worth but if you plan on doing any heavy wheeling with the 3.8l it needs a cooler. The mopar was the easiest back then with all the correct matching brackets and hardware. I'd highly recommend installing the cooler.

 

Hey guys, thanks for the extra info. I had read some years back about switching the OD off and putting the (automatic) trans into 2nd. So this was the case last week, driving up a mild dirt road and the temps were in the mid sixties. I did have a look at trans coolers, but it still strikes me odd that a bolt on cooler would do much when it's already just sixty degrees, and if it were 100 degrees the cooler surely wouldn't lower the temp by 40 degrees? Still, I know it would help, just seems odd.

If you go to about 9:40 in this video, you can see how mild the road is when the hot oil alarm came on.


Thanks again for the ideas.

Shawn

 

In 2nd gear (automatic) the torque converter does not lock up, and that creates a lot of heat. 3rd is where it locks up, that’s why I typical recommend if you’re doing slow speeds, on dirt, put it in 4lo, drive, and turn off overdrive. At higher speeds, just turn off overdrive.

 

Thanks very much YNOWGN. That's what I'll do next time.