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Xj still getting Hot.

Bmfinney

NAXJA Forum User
Location
Arkansas
Guys I’m literally stumped. I’ve had my motor apart 5 times replaced everything on my cooling system. New fan clutch new auxiliary fan. Wired it to a toggle switch. New 180 degree thermostat. New cylinder head. New 2 row radiator. Installed a mechanical temperature guage to I can actually read the temperature. And now when I’m driving around town it stays cool 190 or below. When I get on the interstate and am pulling a hill it climbs to 230. My next option is taking the thermostat out and see how it reads but this thing should be running cold now.
 
The water pump was an auto zone brand not sure which. The thermostat was Napa. The aluminum radiator I got online. Think I’m going to try removing the thermostat see what that does. Then I guess take out the condenser for the ac and clean it. Incase you all have other ideas
 
I would be inclined to believe it is your radiator. I've battled with 4 XJ's (still own all of them) with various degrees of overheating problems. I've done everything and changed everything from custom built radiators, stock radiators, bypass the heater core, changing every part imaginable, blah, blah, blah.

Each time it seems that the radiator is the main culprit. So far, the best options I have found are either the Champion BC1193, or the Spectra Premium 1193 from AutoZone. I have the Cold Case as well, but I don't like that one as much.

Another thing I have found is that a clogged heater core can affect cooling as well. Sometimes those heater cores can bring in debris and corrosion into the system. I have bypassed 2 of them because of of a clog, and the other one was leaking. On the one with the clog, I tried flushing it and a bunch of junk came out. But I still had a lot of debris in the system. I flushed it many times after bypassing the heater core, and it seems to be better. Prior to bypassing the heater core, the supply side hose of the core would get hot and firm with pressure. The return side was cool and considerable less pressure. I suspect faulty heater cores may have something to do with out overheating problems. In all the threads and articles I have read on the internet, and I've read almost all of them, no one ever mentions the heater core. I'm hoping I'm on to something with this. Time will tell.

Do not remove the thermostat. That doesn't fix anything. In fact, you should be using a 195 degree thermostat.

From what I've read and experienced, no one knows the singular cause of XJ's overheating. Most people throw parts at it, or put up with and manage the overheating. I've found that the fan override switch helps the best on my trail rigs. On my son's bone stock 99 DD, the Spectra Premium radiator works great, and he only sees a slight temp creep going up long hills on the freeway.

Here's what I think about the XJ cooling systems. My opinion and experiences only. The stock XJ cooling system is marginal at best from the factory. Because of the design of the front end, the radiator is just too small to be able to dissipate the heat properly. It needs a larger surface area and air flow to do this. Add in a condenser and a trans cooler, and that doesn't help. Stock barely manages to do the job. So then add in years of neglect on many XJ's, and you further tax the system with crud buildup. You can remove some of that by changing parts, or maybe doing flushes, but I'm sure much of that build up stays in the block and head. When you start adding lifts and bigger tires, it taxes the system even more. Other model Jeeps run the same engine with a bigger radiator and don't seem to have nearly the problems XJ's do.

In all my years owning and working on many cars, I've never had trouble diagnosing and fixing cooling problems on any other car I have owned, and I've owned a lot. It was almost always a radiator and thermostat change, along with a good flush, and everything was always back to normal. Sometimes it was a head gasket, but that usually showed up as it's own problem. The XJ's are a whole other animal.

It is an obvious know problem with XJ's, otherwise there would not be this many complaints and problems documented all over the internet. Unfortunately, I have not seen or heard of any viable solutions other than what I have stated. Everyone seems to throw parts at it and hope for the best.
 
Yeah I’m inclined to go back with the original. I installed this aluminum radiator thinking it would help cool it. Gonna go ahead and buy a pressure tester and put pressure on the cooling system for leaks. And check for a cracked block. Never ran into that problem before but I’m really getting tired of working on this thing owned it a year and only have drove it for about a month. Spend more time fixing the thing. Owned a zj before this and it was pretty much the same way had to pull the motor on that. But this has me absolutely flustered. Bought it for the reliability
 
Since you didn't mention the radiator brand/model, I'm guessing that you bought an ebay/Amazon special, but can you report what you're using.
 
Run a 195 stat. 180 will keep it in warm up mode. Do not run without a stat. Even race cars use a restrictor plate. No stat will super heat the rear of the engine and over cool the front. X2 on the radiator culprit. Seen lots of reports of poorly cut cores on those lately. Also check for vacuum leaks.
 
...

Each time it seems that the radiator is the main culprit. So far, the best options I have found are either the Champion BC1193, or the Spectra Premium 1193 from AutoZone. I have the Cold Case as well, but I don't like that one as much.

...

I've got a Cold Case, and its working well, but I'm always game to know if there is anything better. Did you compare a Cold Case back-to-back with a BC1193, or are you certain the BC1193 cools better?
 
I've got a Cold Case, and its working well, but I'm always game to know if there is anything better. Did you compare a Cold Case back-to-back with a BC1193, or are you certain the BC1193 cools better?

They are not in the same Jeep, so I can't make a direct comparison on how well they cool head to head.

The BC1193 looks to be better made than the Cold Case. The workmanship and quality is much better on the Champion. The fitment was relatively the same. Not that the Cold case is a bad radiator, I just like the quality and performance of the Champion better.

Here's what I can tell you about the performance. On my wife's 97 trail rig, I originally ran an American Eagle 2 row radiator. AE is Champions sister company. That radiator was great, never ever got over 210, no matter the outside temp, A/C on, trails, or on the street. Unfortunately, that radiator sprung a leak, and AE no longer makes that one. So I opted to replace it with a Cold Case. It's just okay, it creeps up just over 210 fairly easily. When it's warm outside, my wife says she has to toggle between running the A/C and using the fan override switch. It's manageable, but it's not as good as the AE.

On my 99 trail rig, I tried the Mopar stock one. It worked okay for a time, but after a while, the temps started to creep up. I couldn't really tow my teardrop trailer in hot weather without over heating issues. I think the issues may have been exacerbated by a faulty heater core letting gunk into the system. So I bypassed the heater core, cleaned everything out, and put in the BC1193. So far it's worked really well. Still have a little bit of temp creep when towing, but nothing like the stock Mopar. The BC1193 has worked the best for me.

I've tried other radiators like the CSF 2 row. That one was junk for me. On my 95 trail rig, I had a custom radiator built for it. I had the biggest tanks I could fit made with a 2 row core. I even moved the whole assembly closer to the front of the grill to accommodate not only the bigger core, but for the ZJ fan clutch. Even that one just works okay.

All in all, on all of my trail rigs, the fan override switch helps the most to mitigate the temps. If you shut off the A/C and run the e-fan, all of them will cool way down. Fortunately, I don't need to run the A/C all the time, and most of the time on the road, I can run the A/C no problem. It's towing or on the trail that can give me issues.
 
What year do you have?
 
If the block was cracked and you had the head off. And filled the water ports up with water. Wouldn’t the water level go down after awhile?
 
They are not in the same Jeep, so I can't make a direct comparison on how well they cool head to head.

The BC1193 looks to be better made than the Cold Case. The workmanship and quality is much better on the Champion. The fitment was relatively the same. Not that the Cold case is a bad radiator, I just like the quality and performance of the Champion better.

Here's what I can tell you about the performance. On my wife's 97 trail rig, I originally ran an American Eagle 2 row radiator. AE is Champions sister company. That radiator was great, never ever got over 210, no matter the outside temp, A/C on, trails, or on the street. Unfortunately, that radiator sprung a leak, and AE no longer makes that one. So I opted to replace it with a Cold Case. It's just okay, it creeps up just over 210 fairly easily. When it's warm outside, my wife says she has to toggle between running the A/C and using the fan override switch. It's manageable, but it's not as good as the AE.

On my 99 trail rig, I tried the Mopar stock one. It worked okay for a time, but after a while, the temps started to creep up. I couldn't really tow my teardrop trailer in hot weather without over heating issues. I think the issues may have been exacerbated by a faulty heater core letting gunk into the system. So I bypassed the heater core, cleaned everything out, and put in the BC1193. So far it's worked really well. Still have a little bit of temp creep when towing, but nothing like the stock Mopar. The BC1193 has worked the best for me.

I've tried other radiators like the CSF 2 row. That one was junk for me. On my 95 trail rig, I had a custom radiator built for it. I had the biggest tanks I could fit made with a 2 row core. I even moved the whole assembly closer to the front of the grill to accommodate not only the bigger core, but for the ZJ fan clutch. Even that one just works okay.

All in all, on all of my trail rigs, the fan override switch helps the most to mitigate the temps. If you shut off the A/C and run the e-fan, all of them will cool way down. Fortunately, I don't need to run the A/C all the time, and most of the time on the road, I can run the A/C no problem. It's towing or on the trail that can give me issues.

Thanks. I'll try the BC1193 if my Cold Case springs a leak. And I totally agree on the value of a efan override on the trails.

I bought it from high quality radiator it’s actually made pretty well came with a Chinese radiator cap

Appearance isn't necessarily a good measure of performance. I recommend trying a known good performing radiator as JonnyCat63 said. Assuming you are trying to stay on the budget side, my research on radiators have also found that many people have run the Spectra Premium single row with success as JonnyCat63 said. My XJ came with a single row CSF that worked pretty well.
 
Not to likely, most cracks leak under pressure because they are so fine.
 
Never mind on the gauge. Thanks for the replies. I will go ahead and order a radiator you all recommended. I’ve drove it twice now and got it fairly warm and checked the coolant level and the level hasn’t went down. That has to be the issue
 
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