Running warm.

[Mudderoy]

The engine cooling system running warm.

This has been an issue with my XJ since I lifted and put 32" tires on it.

I made lots of modifications to the cooling system and temps were fine until I got on the highway.

Much later I added a custom front bumper, lights, and a winch and this did NOT make the problem worse, or better.

I assumed I had a head leak and recently replaced the 4.0 with a freshly rebuilt 4.1. I even replaced the single row aluminum plastic with a 2 row all aluminum radiator that is rated for 600 hp. I saw NO change, at least no dramatic change.

Transmission was rebuilt at the end of 2011.

I really don't understand with all the changes I have made that I cannot run my XJ during the summer and keep the temps well below 230 degrees.

If you have a 97+ XJ and you're highway temps on a 95+ degree bright sunny day is 210 (OR LESS!) I'd like to know your configuration.

Lift, tire size, radiator, length of time you drive on the highway.

The length of time is important because I can drive a good 10 miles before seeing the temp get high, sometimes further. It slowly builds.

[Carves]

................. If you have a 97+ XJ and you're highway temps on a 95+ degree bright sunny day is 210 (OR LESS!) I'd like to know your configuration.

Lift, tire size, radiator, length of time you drive on the highway.

The length of time is important because I can drive a good 10 miles before seeing the temp get high, sometimes further. It slowly builds.


97/98 model

Lift ....... 2" ... yeah hardly worth mentioning I know .. :D
Tyres .... 30x9.5 ... as above .. :D

Rad ....... 2row copper/brass ... tranny heat exchanger bypassed,
T'Stat .... 190* .......... no - thats not a typo ... its 190* :D
"Stock" water pump,
"Stock" fanclutch,
10/90 pre-mixed, off the shelf, coolant,

Butt ugly bumper, as per my pics ... still has a bit of an airdam thing happening tho .. ;)

Splash guard removed,

No gaping holes in the bonnet ,,, a little bit of venting happening at the rear corners tho,

Large tranny cooler mounted in front of radiator,

Fair sized driving lights and sometimes a bug screen over the grille.

80*-110*+ ambients ... running temp is 195*-200* ... AirCon Off

Highway time ... normally nothing less than an hour at 60-65 ... but generally 2-3hrs.

[Cheromaniac]

I made lots of modifications to the cooling system and temps were fine until I got on the highway.

I really don't understand with all the changes I have made that I cannot run my XJ during the summer and keep the temps well below 230 degrees.

At highway speeds the operation of the electric fans won't matter 'cause there should be plenty of airflow through the radiator anyway, so there's no issue there.
If you don't already have an auxiliary tranny cooler, I strongly recommend that you install one (B&M stacked plate) and make it as large as possible. You can either have it as a standalone cooler (if winters are mild) or in series with the return line going to the radiator heat exchanger (if winters are cold).
You might also want to check the tension in the drivebelt. There should be no more than 1/2" of deflection along its longest free length, and you shouldn't be able to twist it more than 90* in either direction. A slack belt could have enough slippage to slow down the water pump speed. If the smooth side of the belt has a shiny, glazed appearance, it's a sure sign of slippage and you'd be well advised to replace it.

[Mudderoy]

At highway speeds the operation of the electric fans won't matter 'cause there should be plenty of airflow through the radiator anyway, so there's no issue there.
If you don't already have an auxiliary tranny cooler, I strongly recommend that you install one (B&M stacked plate) and make it as large as possible. You can either have it as a standalone cooler (if winters are mild) or in series with the return line going to the radiator heat exchanger (if winters are cold).
You might also want to check the tension in the drivebelt. There should be no more than 1/2" of deflection along its longest free length, and you shouldn't be able to twist it more than 90* in either direction. A slack belt could have enough slippage to slow down the water pump speed. If the smooth side of the belt has a shiny, glazed appearance, it's a sure sign of slippage and you'd be well advised to replace it.

I have a 13k BTU B&W that I need to install. I had one on before but the hose clamps became lose and then I damaged it with a lost nut that I found after tighting it down on top of it :( So I have purchased another one, just haven't installed it yet. Since I had the problem with the cooler in series with the radiator and aux/factory tranny cooler I believe that I will bypass the radiator all together.

I have a B&M tranny temp gauge now so I'll be able to monitor the tranny temps, which was my concern before. I'm sure the 13k BTU tranny cooler will be enough, but not sure enough to risk the transmission on a hot summers day.

I'll be installing it when I install the 3 electric fans. I'm hopefully that it is the extra effort the transmission is having to make due to the added weight of the add-ons and the tires that is causing the issue. Removing it from the cooling system should make a huge noticeable difference quickly.

The electric fans was an attempt to cool the temps while driving slow or at stops. With the current set up the temps do drop quickly when I'm not moving, just once it get to 230 it stays above 210 and won't drop to 210's unless I sit at idle for 5 to 10 minutes.

[4.3LXJ]

Tony just for giggles take your hood off for a day or two. Ugly I know. When I did it made a world of difference. If it does, then it is an air flow problem. I know that you put the ram hood on, but that is a high pressure area near the windshield and may not be doing you any good. The best place to vent is the front of the hood right behind the radiator like Mark and myself. That is an area of vacuum and will draw more air out

[Fit4Duty]

The engine cooling system running warm.

This has been an issue with my XJ since I lifted and put 32" tires on it.

I made lots of modifications to the cooling system and temps were fine until I got on the highway.

Much later I added a custom front bumper, lights, and a winch and this did NOT make the problem worse, or better.

I assumed I had a head leak and recently replaced the 4.0 with a freshly rebuilt 4.1. I even replaced the single row aluminum plastic with a 2 row all aluminum radiator that is rated for 600 hp. I saw NO change, at least no dramatic change.

Transmission was rebuilt at the end of 2011.

I really don't understand with all the changes I have made that I cannot run my XJ during the summer and keep the temps well below 230 degrees.

If you have a 97+ XJ and you're highway temps on a 95+ degree bright sunny day is 210 (OR LESS!) I'd like to know your configuration.

Lift, tire size, radiator, length of time you drive on the highway.

The length of time is important because I can drive a good 10 miles before seeing the temp get high, sometimes further. It slowly builds.

I have a 97 XJ with 185,000 miles on the clock. It has a Rusty's 3.5" lift and 31x10.5x15 tires. Everything else is stock. Still has the single row radiator.

I live in Phoenix, AZ. For some reason this XJ never goes above 210 even in the summer and while driving on the freeway and offroad.

I also have a 99 XJ that has a Rusty's 4.5" lift with 33x12.50x15 tires. 4.56 gears, front and rear lockers, rock rails, fuel tank skid, transfer case skid, engine skid, front winch bumper with winch and roof rack.

It has 179,000 miles along with a high flow water pump and three row radiator. When the air temp is above 90, this trunk likes to run at or near 230 while on the freeway. And if I am climbing a long hill it will eventually peg the temp needle.

Can't understand how the two can be so different.

[gary63]

your temp. is coming from add weight and lockers putting more load on the engen and I have herd more people have heat problem with 3 row than with 2 row.what we have found is some time the thicker radator give you more coolent but the air gos through and is heated up more that the back row isn't cooling but warming back up.We have found installing a 2 row and a resevor or bigger side tank work better.I'm in Washington in the hellhole of the evergreen state winter around 20 summer around 99-102 so we have to beready for both.

[Mudderoy]

your temp. is coming from add weight and lockers putting more load on the engen and I have herd more people have heat problem with 3 row than with 2 row.what we have found is some time the thicker radator give you more coolent but the air gos through and is heated up more that the back row isn't cooling but warming back up.We have found installing a 2 row and a resevor or bigger side tank work better.I'm in Washington in the hellhole of the evergreen state winter around 20 summer around 99-102 so we have to beready for both.

Tell me more about this reservoir.

Oh! Are you talking about the overflow bottle?

[gary63]

no it is a tank you install some were in the cooling system most put it in the heater hose on the return line if your system dosn't serculate through the hose when the heater is off then you tie it in other way.some guy just have a radater made like a 3 row but with only 2 rom that way they get the bigger tanks on the side but the air pass though only 2 row.

[OrangeXJ]

I think it is the nature of the beast. The 4.0 is going to run around 220. All of mine runs 220 in 30 -100 temps out side. Imho your quest to lower the temp is only going to lower the balance in your pocket book

[gary63]

I would try redline wetter water it that much and helps everthing als will cost you more $ and your jeep may just be one that runs hotter than others.

[EekGirl96]

I had the same problem with my XJ (96), after replacing the radiator, added a tranny cooler and a switch to the fan(that way I can control when the fan comes on and off) my XJ doesnt want to break the 210 mark....

...and thats saying alot coming from an XJ in AZ

[pismo61]

96 cherokee auto. 5 in. of lift 33s with true tracs and 4.56s.I had heat creap and the temp would build on the freeways to 230 and above.I did everything you could do(pump,hoses.radiator,thermostat,temp sensors,housing,block test,fan clutch,yada yada) and nothing helped.The last thing I did was installed a griffon radiator,new a/c condenser,and move the tranny cooler(one with a fan) in different place away from that radiator.No more problems runs no higher than 206 on 100 degree days here in So Cal.The readings were all taken with a scan guage I have.Most the time,(in cooler weather) it runs under 200 and if it drops below 195 you see the thermostat doing its thing keeping the temp above 195.

[89Laredo]

OEM RADIATOR CAP
OEM RADIATOR CAP
OEM RADIATOR CAP
OEM RADIATOR CAP



...OEM RADIATOR CAP!
When is the last time you have tested yours, or put a new one on?

Made a HUGE difference, aftermarket caps are junk. (the 15lb 21yr old GM cap on my moms buick was better than a brand new one from autozone, I still keep it for a backup)

Have you confirmed your readings with an IR thermometer at the thermostat housing (where the temp sender is)?

Im also convinced that air gets trapped in the back of the head and you can never get all of it out, UNLESS you have -96 where you can pull the gauge sender.

Since it barely gets below freezing there I would run less coolant and more DISTILLED water, with an anti corrosion/"water wetter" additive in it.

[Mudderoy]

96 cherokee auto. 5 in. of lift 33s with true tracs and 4.56s.I had heat creap and the temp would build on the freeways to 230 and above.I did everything you could do(pump,hoses.radiator,thermostat,temp sensors,housing,block test,fan clutch,yada yada) and nothing helped.The last thing I did was installed a griffon radiator,new a/c condenser,and move the tranny cooler(one with a fan) in different place away from that radiator.No more problems runs no higher than 206 on 100 degree days here in So Cal.The readings were all taken with a scan guage I have.Most the time,(in cooler weather) it runs under 200 and if it drops below 195 you see the thermostat doing its thing keeping the temp above 195.

I've recently been thinking about getting a new A/C compressor.

[pismo61]

Replacing the condenser,moving the tranny cooler,and the Griffin radiator were the only three things that made the difference.Not sure which one or all did the trick because I did those three things at the same time.Everything else I did before(believe me I changed everything out) and did not help.If I had to guess Id say it was the Griffin rad.and moving the tranny cooler because did clean the original condenser before I did these three things.Although the new condenser from Rock Auto does look more pores.But who knows.

[Mudderoy]

Replacing the condenser,moving the tranny cooler,and the Griffin radiator were the only three things that made the difference.Not sure which one or all did the trick because I did those three things at the same time.Everything else I did before(believe me I changed everything out) and did not help.If I had to guess Id say it was the Griffin rad.and moving the tranny cooler because did clean the original condenser before I did these three things.Although the new condenser from Rock Auto does look more pores.But who knows.

Great, very helpful information. I have a two row all aluminum in mine now, not a Griffin. The only other unknown was the air flow under the Jeep question. If you avatar reflects correctly it seems we both may have a skinny front bumper without an air damn. Safe to assume that you're not running the Jeep (or any) armor under that bumper? You know something that might force more air through the radiator?

[msmoorenburg]

Replacing the condenser,moving the tranny cooler,and the Griffin radiator were the only three things that made the difference.Not sure which one or all did the trick because I did those three things at the same time.Everything else I did before(believe me I changed everything out) and did not help.If I had to guess Id say it was the Griffin rad.and moving the tranny cooler because did clean the original condenser before I did these three things.Although the new condenser from Rock Auto does look more pores.But who knows.

Will the heater run you out of the jeep?

[Mudderoy]

You know I really like Rock Auto but...

SPECTRA PREMIUM / COOLING DEPOT Part # 74895
A/C condenser, is $83.99 with $12.67 shipping.

Spectra Premium 7-4895 A/C Condenser
A/C condenser, is $66.72 and FREE 2 day shipping (Amazon Prime Member).

I want to help support the little(r) guys, but come on!

[Mudderoy]

Will the heater run you out of the jeep?

I have to change my heater core I know, but I also have an unknown leak in my A/C system so this is a win/win.

[pismo61]

Yes, I have the Logans Metal front bumper with the Warn M8000 winch and the Mopar front skid plate is on the Jeep also.

[Mudderoy]

Yes, I have the Logans Metal front bumper with the Warn M8000 winch and the Mopar front skid plate is on the Jeep also.

Mine came with the factory skid, I'm assuming that's what you mean by Mopar, I've been thinking about putting it back on.

[pismo61]

I have run with and without the factory skid plate and it makes no difference in engine temp.Sometimes I ll leave it off because its pain to work on anything under there or see anything.

[Metlic53]

I've got a 97 xj with 31's, 3.55 gears 130 lb winch bumper, winch, rear winch bumper with tire carrier, 150 pounds of speakers in the rear, 4.5 inch lift. I got a k&n CAI, 160 thermostat, 63mm throttle body, neon injectors, my oem radiator has 50k miles on it, it was damaged when the jeep got stolen, they took a screw driver to it. My jeep will never overheat while driving, the other day I had a full crew in the jeep pulling my 18 foot car hauler with my 90 model xj to Houston and even flooring it to keep 60mph it never got over 190. What I've noticed is when mine sits for longer than 10 minutes idling its like the gas vaporizes b4 it can hit the motor then it hits 215 and will hold there, if I rev it up to 4k Rpms for 30 seconds it's fine for another 10 minutes so I don't know about that one. Just hit 184k miles

[4.3LXJ]

Clutch fan is getting a little weak

[Metlic53]

Clutch fan is getting a little weak

Sorry to thread jack, you think it's that? Ill grab another one, that's what my dad told me but then he felt it and said huh maybe not seems good

[Mudderoy]

I have run with and without the factory skid plate and it makes no difference in engine temp.Sometimes I ll leave it off because its pain to work on anything under there or see anything.

That's why I have mine off.

[4.3LXJ]

Sorry to thread jack, you think it's that? Ill grab another one, that's what my dad told me but then he felt it and said huh maybe not seems good

That is what my son's YJ did. We replaced the clutch and it stopped