WJCO's Build Thread, 1999 WJ

[WJCO]

Sorry to hear the cat didn’t fix the issue... I was almost certain that would fix it by the sound of what you were saying.


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Me too.

Is it possible the coolant is flowing too fast? Are you using an OEM pressure/temp thermostat?

Just tossing it out there. Might be a long shot. With one of my old cars I had unrestricted (no thermostats) and it would over heat because the coolant wasn’t in the radiator long enough. I restricted it and it cooled right down. Especially at idle with only the fan pulling air.

Also. Where is the oil and trans cooler located, in the tanks of the rad? Are the lines free of kinks and build up?
Hmm...Are you sure it’s no sucking air from the heater core leak? Fuck man. Feel for you. I hate these type of issues.

I've considered the flow being too fast, but it never acted up at idle prior to last year. I've put two tstats in from the parts store but may consider OEM. But again, one of these tstats was in there for a couple of years and worked fine prior. Still acts up with the heater core bypassed so I've definitely ruled that out.

Have you tried a lower temp thermostat?

I've done that in the past on other vehicles and it really doesn't do much good on newer vehicles. All of the sensors are based on 195f ECT temp, so by lowering it, it can cause driveability issues. Also, what's going on with mine, it appears the engine is getting too hot, so even with a lower temp tstats, that may delay the issue, but at some point, the cooling system still won't be able to remove the heat.

 

[TrailHunter]

Hows your Oil pressure? Cruising vs at a stop... Normal numbers?

 

[WJCO]

Hows your Oil pressure? Cruising vs at a stop... Normal numbers?

The gauge shows it in spec. What are you thinking?

 

[TrailHunter]

The gauge shows it in spec. What are you thinking?

Low oil pressures/bad circulation which could cause the engine to overheat?? I did a search and some issues actually came up... but they were showing low pressure numbers...

 

[WJCO]

Low oil pressures/bad circulation which could cause the engine to overheat?? I did a search and some issues actually came up... but they were showing low pressure numbers...

I see what you're saying. I think all that is good. Gauge reading fine, no noises, no MILs, etc.

 

[OverlanderJK]

I didn’t read this whole thing but are you saying it overheats in hot days with the ac on?


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[WJCO]

I didn’t read this whole thing but are you saying it overheats in hot days with the ac on?


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It started that way last year. It would do it pretty much only at idle. With ac off, it would do it but took like 30 minutes to start acting up. With ac on at idle, it would happen pretty much immediately. It just started one day last July and has been that way ever since.

So, I finally replaced the radiator last week as that was the only thing left. It still does it, but now it overheats on the highway also or while going up mountain hills. And it still acts up at idle with ac on. I tried driving up the mountain yesterday and even with heater on full blast, after 15 minutes, temps wouldn't drop. Back at home with a laser, new radiator is definitely removing heat, just not removing enough.

 

[OverlanderJK]

It started that way last year. It would do it pretty much only at idle. With ac off, it would do it but took like 30 minutes to start acting up. With ac on at idle, it would happen pretty much immediately. It just started one day last July and has been that way ever since.

So, I finally replaced the radiator last week as that was the only thing left. It still does it, but now it overheats on the highway also or while going up mountain hills. And it still acts up at idle with ac on. I tried driving up the mountain yesterday and even with heater on full blast, after 15 minutes, temps wouldn't drop. Back at home with a laser, new radiator is definitely removing heat, just not removing enough.

Got it. I’m no help but thought it was doing it under load with ac on. Was going to say, umm that’s bigger tires for you. Lol good luck


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[wayoflife]

Well shit, that sucks. Assuming your fan and or fan clutch if you have one is working properly, I'm kind of at a loss especially being that you just replaced the radiator. Could still be that you have air in the system or some kind of blockage but if all your hoses are getting hot, that should rule that out.

 

[Zstairlessone]

I’m sure you’ve looked (a million times), but how is the shroud?


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[fiend]

Sorry if this point has already been covered, but maybe you’re not overheating at all and it’s just a broken temp sensor/gauge.

 

[WJCO]

I’m sure you’ve looked (a million times), but how is the shroud?


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All good.

Sorry if this point has already been covered, but maybe you’re not overheating at all and it’s just a broken temp sensor/gauge.

I checked that originally. I can feel the heat in the floorboards when it starts to act up and a laser gun confirms that temps are rising.

 

[WJCO]

So, during the process of repairs, my bleeder screw got so tight that when I tried to remove it, the hex head stripped out



So I bought another Dodge upper hose with a cap built in so that I could at least bleed the system.



And I changed the water pump again. I confirmed that flow is good and yet it is still doing the same thing. Good thing is that I can literally change this pump in under 30 minutes now.

I threw in the fucking towel and dropped it off at the dealer. I parked it near the JLs for good luck.

 

[Andy5160]

You are not alone today [emoji23][emoji23]
Good Luck


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[JKbrick]

Does the Evans waterless coolant or whatever it is remove more heat? I see it advertised but don’t know what it is. Another product makes water wetter but can’t think of the name of it, May both be gimmicks. Is there any way your coolants got mixed up and gelled?


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[black pearl]

Long shot but... I have heard of plugged or really dirty transmission filters adding heat to a radiator, causing temps to rise. That is if your cooler lines run through the radiator. Grasping at straws on ideas.


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[notnalc68]

So, during the process of repairs, my bleeder screw got so tight that when I tried to remove it, the hex head stripped out

View attachment 302942

So I bought another Dodge upper hose with a cap built in so that I could at least bleed the system.

View attachment 302943

And I changed the water pump again. I confirmed that flow is good and yet it is still doing the same thing. Good thing is that I can literally change this pump in under 30 minutes now.

I threw in the fucking towel and dropped it off at the dealer. I parked it near the JLs for good luck.

View attachment 302944

That sucks. I’m over Grand Cherokees, for a little while, lol.


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[sipafz]

So, during the process of repairs, my bleeder screw got so tight that when I tried to remove it, the hex head stripped out

View attachment 302942

So I bought another Dodge upper hose with a cap built in so that I could at least bleed the system.

View attachment 302943

And I changed the water pump again. I confirmed that flow is good and yet it is still doing the same thing. Good thing is that I can literally change this pump in under 30 minutes now.

I threw in the fucking towel and dropped it off at the dealer. I parked it near the JLs for good luck.

View attachment 302944

Just a dumb question and maybe I missed it, but did you check the cap to see if it’s holding pressure?

 

[WJCO]

Does the Evans waterless coolant or whatever it is remove more heat? I see it advertised but don’t know what it is. Another product makes water wetter but can’t think of the name of it, May both be gimmicks. Is there any way your coolants got mixed up and gelled?


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Supposedly, water itself is the best for heat transfer. However, it lacks lubrication and causes corrosion and freezes in the winter. With that being said, by the time I got done doing multiple repairs, I was running at least 60% water. No change.

Long shot but... I have heard of plugged or really dirty transmission filters adding heat to a radiator, causing temps to rise. That is if your cooler lines run through the radiator. Grasping at straws on ideas.


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The V8 WJ towing package has 2 transmission coolers. An external air cooler and an internal radiator cooler. I've checked both and they are fine prior to cooling system heating up. I've tripple checked that, lol. Also, I have a trans temp MIL and it's never illuminated.

That sucks. I’m over Grand Cherokees, for a little while, lol.


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I hear you. Truthfully when we purchased this, it was a cost decision. It was 3600 bucks. We knew from the get-go that no matter what went wrong, it would still be cheaper than a JK even if we had to repair it. We've built it up way beyond our original intentions and it's taken us further than we thought we would go. So, at this point, worse case is an engine replacement. As bitter as that sounds, it is what it is. I'm really hoping the dealer calls with some out of whack sensor causing a lean air/fuel mixture and I can just move on. But, if the call is an un-lubed financial raping, I'm prepared for it, I guess....

 

[WJCO]

Just a dumb question and maybe I missed it, but did you check the cap to see if it’s holding pressure?

Cap is brand new.