Overheating problem

Dvaniwaarden11 said:
Just took the Jeep on the freeway to try and replicate my issues. With AC full blast driving in 5th gear I got it to overheat. Top of the radiator was 245-50 degrees. Top hose was 260. Sat on the side of the highway for 10 minutes and it went back down to 215-220 from being at 240 when I stopped.
This give anyone some lightbulbs going off? Or is it just a bum radiator? Could my thermostat not be engaging? If my thermostat wasn’t engaging my top hose wouldn’t be that hot right?

The mechanic that did my engine swap keeps thinking it’s my winch blocking my radiator, but that still doesn’t seem right to me.
Click to expand...

Simple fix, pull the winch off, give the radiator full air no restriction, and then have your mechanic that did the engine swap see the result. Eliminate that variable. There are thousands of TJ's that have winches on the front, I doubt it would be the issue, and would concern me that my mechanic thinks that, but eliminate it and find out.
 
  • Like
Reactions: Danarch, Dvaniwaarden11, xXDavidCXx and 2 others
Here's my 97 4.0 AX-15. No overheating issues here with this winch.

IMG20240701144534.jpg


-Mac
 
  • Like
Reactions: Dvaniwaarden11
JKP said:
It only overheats on the hwy.

It's either the winch blocking the rad, or a combination of the winch blocking the rad and an aftermarket rad.

Maybe a different rad would bring it down some, but there's no way to know until you stab in another radiator.

Take a photo dead on from the front center of the grill and look at how much of the grill is blocked by the winch.

Or, remove the winch and do your test drive and compare temps.
Click to expand...

Way too many folks run a winch on a TJ in this part of the world for the winch to be the problem.
 
  • Like
Reactions: MikeE024, Dvaniwaarden11, xXDavidCXx and 1 other person
JKP said:
It only overheats on the hwy.

It's either the winch blocking the rad, or a combination of the winch blocking the rad and an aftermarket rad.

Maybe a different rad would bring it down some, but there's no way to know until you stab in another radiator.

Take a photo dead on from the front center of the grill and look at how much of the grill is blocked by the winch.

Or, remove the winch and do your test drive and compare temps.
Click to expand...

IMG_6225.jpeg
 
mrblaine said:
If you brought it to me with those symptoms, I'd say the radiator was junk.
Click to expand...

I know your mechanic, and a few folks on this thread are banging away at having the winch on the TJ like 1000's of other TJ's is your problem, and you're struggling with that.

My suggestion is to go back to the first page, and read this post. All the symptoms point to the problem in this post, all of the data suggests this is the most probable place to start. I would act on that, and if Mopar is not in the cards, start looking for other brands that folks are saying do well, that will take a couple days to get.

In the mean time, it's a few Torx bolts and disconnecting cables, and you can prove the low probability Winch mounted cause right or wrong, and have your fix, or move on to the actual fix without wondering.

I get your frustration, I went through ALL of this....and got a new radiator, and lo and behold, it ran at 204 to 210 in 105 degree heat AC on in Texas. I get your frustration.
 
  • Like
Reactions: xXDavidCXx, Dvaniwaarden11 and macleanflood
Dvaniwaarden11 said:
Just took the Jeep on the freeway to try and replicate my issues. With AC full blast driving in 5th gear I got it to overheat. Top of the radiator was 245-50 degrees. Top hose was 260. Sat on the side of the highway for 10 minutes and it went back down to 215-220 from being at 240 when I stopped.
This give anyone some lightbulbs going off? Or is it just a bum radiator? Could my thermostat not be engaging? If my thermostat wasn’t engaging my top hose wouldn’t be that hot right?

The mechanic that did my engine swap keeps thinking it’s my winch blocking my radiator, but that still doesn’t seem right to me.
Click to expand...

If you are good except for on the highway then my money is on it being a plugged radiator or bad radiator. I say this bc that’s been my experience multiple times.

For reference, I have a winch, two coolers in the grill, and now boost…and all is good except for on the highway when my Mopar radiator gets plugged up from rust flakes from the block. It was an issue before I added the coolers or turbo.

I would not remove the winch.

If you don’t have a Mopar radiator, it could be the radiator or it could simply be plugged.

If don’t want to do a back flush and you can’t find a Mopar radiator, consider trying a Denso that a member has had good luck with.

Removing the winch is a waste of time imo. Your grill is seeing a ton of CFM on the highway, and high air flow can’t fix a radiator that’s not flowing liquid properly.

I generally agree with your upper radiator hose assessment. If your thermostat wasn’t opening it would overheat your engine in idle rather than cool it in idle….especially after pulling over on the highway. This is another indicator that it’s not your water pump or thermostat so u should look to your radiator.

I would flush and back flush the radiator. Do the radiator core too while your in there (as preventative maintenance). You can always do a thermocure flush as well if the system is rusty.

If you’d rather not do that work, or if it doesn’t help, then I’d get a new radiator.
 
Last edited:
  • Like
Reactions: xXDavidCXx, Dvaniwaarden11 and macleanflood
Dvaniwaarden11 said:
Hows it going fellas. I've got an overheating problem with my 1997 TJ 4.0 5 speed. 4.88 gearing on 35s.

My Tj has a brand new motor in it with probably only 2-3k miles on it. When my shop put the new 4.0 in, they replaced every part of the cooling system. Radiator, pump, thermostat, hoses etc are all new.

Since its started to heat up in california and we're into the 90s now, I've been taking my jeep on some longer drives. I've also been using the air conditioning. After about 45 minutes of highway driving (65-75 mph) my gauge reads at 230, and then eventually moves into the bottom part of the red on the gauge. (I don't think the gauge is the issue because the cold AC air would turn into lukewarm air and the floorpan would be noticeably warmer)
When this happened a couple days ago I would lift off the gas and coast in gear until I was at 45-50 mph in the slow lane to let the engine cool using air flow and not putting any load on the engine. It would eventually move back down to 210 and I limped it the rest of the way home. I don't have any issues driving on the side streets of any overheating and I have zero leaks anywhere. My fan clutch has resistance, I have plenty of fluid and nothing using coolant, and the entire cooling system is new. I have a winch on the front of my jeep but I doubt that is an issue in airflow because that doesn't make sense to me. I'm at a loss for what the issue could be. Is running my AC at a higher speed causing too much load on the engine? Any ideas for a direction I can start looking in?

On a cooler day if I would ever be driving up a long hill my engine would get hot and I would just limp the way to the top of the hill but I felt that had more to do with my 4.88 gearing and figured that its a jeep and I should expect to do 65 going up a long hill, but maybe I'm wrong and my jeep should be able to do that no problem?

Would just love some advice.
Thanks,
Dylan
Click to expand...

Your gearing isn’t causing you to overheat, the lower gearing helps turn the water pump more at higher RPMs so it’s actually a good thing.

Since you haven’t reported issues when driving slow or idling, the facts point to it being a radiator related issue. That’s where I would focus my attention.

If it was the fan clutch, thermostat, or WP, you’d likely have a bad time trying to cool the engine in idle after pulling off the highway on a hot day.
 
  • Like
Reactions: Dvaniwaarden11
cpwolf said:
I know your mechanic, and a few folks on this thread are banging away at having the winch on the TJ like 1000's of other TJ's is your problem, and you're struggling with that.

My suggestion is to go back to the first page, and read this post. All the symptoms point to the problem in this post, all of the data suggests this is the most probable place to start. I would act on that, and if Mopar is not in the cards, start looking for other brands that folks are saying do well, that will take a couple days to get.

In the mean time, it's a few Torx bolts and disconnecting cables, and you can prove the low probability Winch mounted cause right or wrong, and have your fix, or move on to the actual fix without wondering.

I get your frustration, I went through ALL of this....and got a new radiator, and lo and behold, it ran at 204 to 210 in 105 degree heat AC on in Texas. I get your frustration.
Click to expand...

Yeah. I keep hoping I see the mystery answer on here that will solve my problem without having to buy new parts. But I agree, I just need to get over it, accept that this is what I signed on to when I first bought my Jeep, and fix the part that everyone says I should. Haha.
 
Dvaniwaarden11 said:
Yeah. I keep hoping I see the mystery answer on here that will solve my problem without having to buy new parts. But I agree, I just need to get over it, accept that this is what I signed on to when I first bought my Jeep, and fix the part that everyone says I should. Haha.
Click to expand...

You could always tell the installer that he installed a bad radiator if that’s what ends up happening. Maybe you can get a replacement under warranty or a refund (preferably).

But regardless, I’d rather not break very expensive parts simply because I don’t want to pay for a part. Unfortunately, we don’t get to choose what’s broken.
 
  • Like
Reactions: Dvaniwaarden11
MikeE024 said:
You could always tell the installer that he installed a bad radiator if that’s what ends up happening. Maybe you can get a replacement under warranty or a refund (preferably).

But regardless, I’d rather not break very expensive parts simply because I don’t want to pay for a part. Unfortunately, we don’t get to choose what’s broken.
Click to expand...

That’s what I’m going to pivot to. The guy who put my new motor in was the family mechanic for the last 30 years. Pretty sure he’ll take care of it. Granted, I’ve had to replace radiators before so either way hopefully a couple hundred dollars and a beer or two (a few) and I’ll be back on easy street.
 
Dvaniwaarden11 said:
That’s what I’m going to pivot to. The guy who put my new motor in was the family mechanic for the last 30 years. Pretty sure he’ll take care of it. Granted, I’ve had to replace radiators before so either way hopefully a couple hundred dollars and a beer or two (a few) and I’ll be back on easy street.
Click to expand...

I’d probably ask your guy what brand the current radiator is and see if you can try something different (assuming it’s not Mopar).
 
  • Like
Reactions: Dvaniwaarden11
Top Bottom
Back