Help Fixing Overheating Issue

R

reece_price

New member
I would like some help trying to figure out a overheating issue on my JKUR. Background 100k miles 37s 5.13 gears automatic. Metal bumpers and full under belly skids.

So my Jeep stays mostly cool. I can cruise around drive highway up to 65 ish and it stays at around 223ish that's with AC on full blast. But if I start going above the 65ish 3k RPM range it starts to heat up. It's not immediate, but it's starts warming up. I just did a full coolant flush and it seems a little better, but still a problem. Using a scan tool I pushed it before the flush and temp got up to 238 before I let off the throttle, it then cooled back down to 220 while cruising at 60ish.

When the engine is cool I start it up and the temp climbs quickly like it should then it levels out around 220 at idle. Which tells me the thermostat is working. It is a replacement unit from auto parts store, old one stuck closed on me and had to replace it.

I can crawl around off road and it's fine. It's just the highway speed it does not like.

Any help would be appreciated. I'm debating gutting the whole coolant system and replacing it all because everything has 100K miles on it.

My ideas would be water-pump is worn and not moving coolant efficiently around, or thermostat is not opening fully.
 
For sure, the JKs have to have clear air flow. Start there and see if it makes a difference.

I ran into an odd temp situation with mine. It’s been running warm to hot for over a year after having the dealership change the fluids and filters on the trans and TC. After long runs would find a bit of trans fluid had come out the dip stick. It never thru a code or gave me a engine light do I just Ignored it. Checked the fluid level and it was way above the hot set of holes even when the Jeep was cold. The lovely dealership overfilled it by two quarts as compared to when I refilled it after doing a quick fluid swap. Both trans and engine dropped 15-20 degrees after the fluid change and correct fluid level. Once again, learned my lesson about take it in.

The short version is check your fluid levels and air filter to to make everything’s at the right level and clean as well.


2015 JKUR AEV JK350
1985 CJ8 Scrambler
 
wjtstudios said:
Try removing the winch and see if it helps. I’d bet you’ll see a difference.


2015 JKUR AEV JK350
1985 CJ8 Scrambler
Click to expand...

Yup, pull the winch, the license plate , the stinger. That shit all either blocks or messes with air pattern flow at speed. EVO makes a good bumper that will lower that winch and get it between your frame rails and out of the way of your grill.


Sent from my iPhone using WAYALIFE mobile app
 
64fabius said:
Hi, have you checked the electric fan? Does it work fine?
Click to expand...

The fan is working I can hear and see it come on.

Abntroop said:
Yup, pull the winch, the license plate , the stinger. That shit all either blocks or messes with air pattern flow at speed. EVO makes a good bumper that will lower that winch and get it between your frame rails and out of the way of your grill.


Sent from my iPhone using WAYALIFE mobile app
Click to expand...


This is actually a bumper I fabricated from scratch. I have been thinking about a redesign to move winch in-between frame rails. Gonna remove winch and see how much of a difference it makes.

I am also gonna do a transmission fluid/filter change. The filter has never been changed, some of the fluid was replaced when transmission cooler line connection blew apart a while back. Its possible the filter being old and clogged is causing extra heat.
 
Last edited:
I had the same issues with my Jeep overheating. The temp gauge would get to 3/4 when I got past 60 mph on the highway and the Air Conditoner would not work well. I swapped my front bumper with an EVO Quater Pounder and now I can cruise at 75 mph with no issues. The temp guage is slightly below the half way mark and A/C is kicking again. Here is a before and after picture.
 

Attachments

  • EVO Bumper and Stinger Bar.jpg
    EVO Bumper and Stinger Bar.jpg
    108.2 KB · Views: 70
  • IMG_6867.jpg
    IMG_6867.jpg
    81.9 KB · Views: 68
  • IMG_6873.jpg
    IMG_6873.jpg
    81.8 KB · Views: 68
Last edited:
One thing I've always wondered.

Engine/trans skids.....

While camping in cold weather shortly after buying my 2011 jk I had to "squat" next to my Jeep and remember thinking I was a GENIUS! For leaving the engine running, that nice hot air coming out from underneath sure kept me from freezing my a.....ny way, you get the point.

I wonder if the underbody skids are somehow trapping the air that's being pulled/pushed through the radiator?, Because if you don't have a void for the air to go out into, then it's just stuck in there, creating an obstruction just as one in FRONT of the radiator ......

Possible?......

At low speeds, the water pump is moving slower so, the coolant sits in the radiator longer, allowing it to cool down more, therefore negating the trapped air in the engine bay, but, add to that water pump speed , engine speed(more heat), and more wind flow underneath blocking the trapped air and Bam!.....make sense?....

I have a manual jk, live in the desert, no added skids, run in 110*+down to the 20*- range, it runs 195* to 200* under most situations, turn on the AC and go a bit slow and I've seen 213* at the highest, never seen 220*.....ever.

I run straight distilled water with waterwetter.

Maybe something to look into?....

I would pull the radiator and clean it with medium pressure from the back to the front, toss some simple green on it and let it soak(opposite the natural flow of air while installed), this way you flush out and not jamm it deeper into the radiator. Then, using a light behind the radiator, make sure you got it all out!.

My thoughts.....

Good luck.

Sent from my BLA-A09 using Tapatalk
 
gonzzo said:
One thing I've always wondered.

Engine/trans skids.....

While camping in cold weather shortly after buying my 2011 jk I had to "squat" next to my Jeep and remember thinking I was a GENIUS! For leaving the engine running, that nice hot air coming out from underneath sure kept me from freezing my a.....ny way, you get the point.

I wonder if the underbody skids are somehow trapping the air that's being pulled/pushed through the radiator?, Because if you don't have a void for the air to go out into, then it's just stuck in there, creating an obstruction just as one in FRONT of the radiator ......

Possible?......

At low speeds, the water pump is moving slower so, the coolant sits in the radiator longer, allowing it to cool down more, therefore negating the trapped air in the engine bay, but, add to that water pump speed , engine speed(more heat), and more wind flow underneath blocking the trapped air and Bam!.....make sense?....

I have a manual jk, live in the desert, no added skids, run in 110*+down to the 20*- range, it runs 195* to 200* under most situations, turn on the AC and go a bit slow and I've seen 213* at the highest, never seen 220*.....ever.

I run straight distilled water with waterwetter.

Maybe something to look into?....

I would pull the radiator and clean it with medium pressure from the back to the front, toss some simple green on it and let it soak(opposite the natural flow of air while installed), this way you flush out and not jamm it deeper into the radiator. Then, using a light behind the radiator, make sure you got it all out!.

My thoughts.....

Good luck.

Sent from my BLA-A09 using Tapatalk
Click to expand...

Skid plates not designed correctly can definitely keep heat in.
 
Update, took the winch, bumper, etc off. I was able to cruise at 75 80 and it ran around 223-225 which is great. If I really pushed it like 5k+rpm 90mph for extended periods it started to warm up. But that is expected.

Already making plans to build a new bumper with recessed winch. It's gonna be similar to Evo with stinger, but it's going to go out to edge of grill instead of stopping just past frame rails.

I'll make sure and post a build tread.
 
reece_price said:
Update, took the winch, bumper, etc off. I was able to cruise at 75 80 and it ran around 223-225 which is great. If I really pushed it like 5k+rpm 90mph for extended periods it started to warm up. But that is expected.

Already making plans to build a new bumper with recessed winch. It's gonna be similar to Evo with stinger, but it's going to go out to edge of grill instead of stopping just past frame rails.

I'll make sure and post a build tread.
Click to expand...

Well, that’s a start. Still running a little warm. [emoji848] I notice since stripping mine down I’m around 185-210 from 218 avg (before trip, around town avg w. No trailer ) to 243 pulling the trailer at 70mph on this last trip and never getting below 225


Sent from my iPhone using WAYALIFE mobile app
 
Abntroop said:
Well, that’s a start. Still running a little warm. [emoji848] I notice since stripping mine down I’m around 185-210 from 218 avg (before trip, around town avg w. No trailer ) to 243 pulling the trailer at 70mph on this last trip and never getting below 225

Sent from my iPhone using WAYALIFE mobile app
Click to expand...

That temp was running 80 at 3300ish rpm. With 5.13 I run higher rpm so additional heat is kinda expected. It also got up to 225 for a quick second then cooler back to 221-223
 
Last edited:
You must log in or register to reply here.
Top Bottom