Why Your Jeep Cherokee XJ Overheats 

Yeah to start guys are running 20 years on up in age jeeps and thinking the parts don't get clogged or parts dont wear out. I replaced everything to do with cooling never a overheat problem. These rigs are old give them some luv.

My neighbor is a former Kenosha engine plant employee, where the 4.0 L engines were built. I have a 2000 xj, and we started talking about the motor. He said that despite what the internet says, leave the motor with stock OEM parts. The AMC / Chrysler engineers knew what they were doing. Also, he said the 0331 head issues are bullshit. While they may be more prone to the notorious crack between #3 and #4 cylinders... All heads will crack if you overheat them and run them too hard. Keep up on maintaining the cooling system and that motor is bulletproof. He said the dumbest thing Chrysler ever did was kill 4.0 production in 2006.

The best thing I did for my 98 was replace the OE thermostat. I did it with a 195* unit. Dropped my average temps about 15*. Next I replaced the fan clutch. That kept my temps from ever going over 220*. Last I change out the coolant every 5 years religiously.

Glad to be seeing some more xj videos💯💯

If the water pump impeller gets degraded (it’s usually plastic) it can absolutely decreases cooling as the pressure gets reduced. I had this happen with a Napa water pump on a 97’ XJ and it hit 250f! Swapped it out for a hesco with a billet impeller and temps dropped to 200f.

Thumbs up if you believe the Cherokee XJ deserves its legendary status in the world of offroading!

Jeep is still looking great. Always appreciate your sharing what you know. I've made some mods to my Bumble Jeep along the cooling lines. All aluminum rad, 4 core, high volume water pump. I always flush the cooling system in the fall. The one thing I did that I'm going to undo is a 160 thermostat. That has messed with my fuel milage. Still rocking the OG 4.0L, about to hit 220k. Again great stuff as usual. God bless, stay well. Merry Christmas.

What I found for the 4.0 that really helped was good hood ventilation so that heat could escape easier and cheap of course a good fan 👍🏼

Good video, good advice. Two more things to check -Lower radiator hose spring -Damaged ac condenser blocking flow to the radiator.

In a bit over a year Ive put 20k miles on my XJ and it only overheated once when the water pump failed. Replaced that and the stat, no problems since. IMO it only overheats when something needs fixing. Edit: stock I6 on mine, heater box valve still functioning.

Great video except for one thing. You completely missed one of the easiest fixes that absolutely will overheat your engine if not addressed. #1 test your radiator cap, or just replace it with new because they are so cheap. I had a bad cap on my Jeep when I first bought it and fought overheating for a while before someone enlightened me about the cap. New cap, overheating was much less of an issue....but still an issue. The next year I read about testing the fan clutch and sure enough, mine was bad. When I put a new fan clutch on, all problems gone. And I mean gone. I put in a ZJ fan clutch just to be safe as I do a lot of sand wheeling that really heats things up. I do have a new thermostat, housing, pump, Hoses, radiator, temp sensor, hood vents, and I drain and fill coolant every fall. But, cap and clutch were my issues. I tried a 180 thermostat and found that all it did was keep my engine at an annoying temperature during fall through spring. In the summer, after 20 minutes, the engine temp rises to 200 regardless. And wheeling, there is no difference. 195 thermostat with a functioning cooling system is perfect.

My fan is ALWAYS on...bought it that way. Its fully rhino lined, hood inluced (it now weights a metric ton!) Also bedliners make for a nice little thermal oven effect thing going on lol. Needles to say, she doesnt overheat. Its also 21F...that helps. I have more electrical gremlins. Like how I turn the ignition off, pull the key out...but she still runs, for 10 seconds. Consistently though...so theres that. Also, I think its related to the ADR. She stumbples a bit, but wont die out, and only once after about 5-8 minutes of running. Very weird. Might also be that PIDM module (I think its called a PIDM...Jeep/Ram names for parts are weird lol) But I love it. Just took her out for a leisurely stroll...best thing? Some Jackalope had his brights...so I turn on my light bare, mounted up high. Yes, him and his retinas got the message. Love your Jeep. Looks amazing!

Also having those heat shields on around the injectors is pretty critical because the header is right below the injectors so you’ll want that heat shield there to keep the hear down off the injectors.

You didn’t cover double row radiators. Whats your thoughts on them for the 4.0s?

My 89 had issues. Flushed the system and got the secondary fan working when the AC was on. After that we put on the shroud for that fan and replaced the clutch on the mechanical fan. After all that we changed out the thermostat. Still heated up. Found out that the thermo-coupler sending unit was bad. Replaced that and she runs right at 190 now all day long.

good video you hit all the points spot on

I resurrected a’98 with 102K on it. I used a FlowKooler pump Hesco high output water outlet and a Robert Shaw thermostat. Running nice.

Adding to the whole "Exhaust Leak Theory" with the head gasket, check your exhaust manifold for cracks/leaks. If that thing is cracked/leaking the heat soak on to the intake and fuel systems gets real.

I'm rebuilding my 2.5l YJ.. Installed a Golen Stroker Motor and went from an AX5 to ax-15 transmission and rebuilt my NP231J Added a new cold case Radiator (67-72) model with dual 14" Spal brushless fans in the back of my jeep..then realized I needed to add a booster pump oarrrr, add a Davis Craig EWP150 32 gallons per minute Removed the thermostat from the housing and installed a new high flow housing and removed the flow cool high flow water pump.. cut the fan blades so there's no blockage..all in all (started building my jeep in Mid January... Still building and learning..let you know how it turns out..

great vid couldnt agree more but my xj with 340k on it runs 200-205 and can be 90 here in az lol also do you have vid bout your fender flares are those tj

Installing that remote switch to your auxiliary fan works great so whenever your off-roading you can just manually switch it on.

If 215 is not over heating why the heck does it spew coolant everywhere every time it gets above that temp?

Something you didn't mention was fuel injectors and intercooler. Diesel injectors play an important role, if they are out of spec they can make the engine run hotter. And an intercooler will drop the exhaust gas temps even more. Make sure to check that out as well.

Heck yeah brother!!

I did have unusual instance of the engine almost overheating at low speeds (street driving), but it would cool at high speeds (highway, freeway). It turned out that the thermostat on the fan clutch had broken, so wasn’t engaging the fan at all -high speeds cooled because of more forced air. After replacing the fan clutch, the problem went away. Mine is a 93 xj with the inline 6 and 5 speed manual.!

I have a 96 Xj you know how I solved that problem 🤷🏼‍♂️ I swapped a 6.0 ls problem solved plus when I smash that skinny pedal I have a grin from ear to ear America 🇺🇸💪🏼🦅🛠️🤙🏼

DO NOT remove the thermostat, too much waterflow will cause your engine to overheat, because the coolant isn't going slow enough to soak in and transfer the heat to the radiator gut the thermostat out if you cant get one (if your on a trail/side of the road), you need flow resistance to slow down the coolant so it can move the heat properly.

New 3-core brass radiator, ditched the fan clutch, reverse flow flex fan, new oem e-fan, end of problem ,even with no fan shroud.

I live in Mexico, replace radiator, water pump cooling hoses new thermostat etc. not until I removed the thermostat completely the overheating issues went away, now my 2000 cherokee runs way better and cooler ! not sure if this will work in your area where winters are way more colder I mean we never see freezing temps where I live

Im getting ready to build an xj but I'm going with a 400 sbc with 3/4 ton running gear

Your XJ looks awesome man! I have also turbo diesel XJ but with factory installed engine. She likes to run hot! 😆 Are those 33s?

Hey man what roof rack is that? Been looking at getting one and it looks like that is pretty good quality.

wow about time some one gives good advice people should listin to this iam tired of fiting with know it alls and yes i have a built 1997 xj

Okay the first part made me Laugh

I have run into a lot of Cherokees that have bad water pumps. The splines end up disintegrating and so it's just rotating little nubs of the pump so it's not cooling effectively. Don't just dismiss a water pump.

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You know you forgot one important ingredient. Cherokees came with a one row core. Change it to a three row making sure you keep an air spacing between the evaporator or any oil cooler in the front.

I saw the exhaust in the B-Role of the jeep, and thought that was excessive for the 4.0😂, but then i heard it. What diesel is that? 5.9?

I just replaced the entire cooling system for 250 dollars. Fan clutch, thermostat, hoses, rad, belt, and water pump. No issues since.

my ZJ never overheats, even when I blew the radiator and the headgasket... overheating isn't one of my problems... headliner and a little rust is my problem now

1 more thing. Stop putting 33’s on your Jeep with stock gearing you’re going to push that engine hard.

You need a new radiator. Get a trans cooler. Make sure the fan clutch is working. I bought a bigger radiator for my 98 zj and it stays cool in Texas weather.

Mine actually runs cold for some reason

Idk about yall but i have overcooling. Replaced the idiot temperature sensor also. So no doubt there. Also replace thermostat 3 times just to make sure.

Like the diesel..

Everyone always says these overheat. Mine is an 88, only the clutch driven fan, no electric fan, no shroud... Towing, uphill up some mean grades, speeding.... She's never overheats. Zero upgrades, just 31s and a camper shell. I just keep her tip top. Edit: I didn't remove the shroud. It was bought like that. My normal is 110ish. I must have a funky sensor or dash. Oem temp thermostat is what's in it.... 195 I think. Either way she runs greaaaaaat.

Same side for intake and exhaust ports. I always thought that was a cool, yet flawed design. Heat soak is almost guaranteed

I have an XJ that rarely hit 200 and one that runs at 200-215

Great advice! Go through everything in your cooling system before you start cutting holes in your hood in an attempt to lower temps. Bleepin Jeep has a great video on flushing your coolant system. Check it out first. Beautiful XJ btw! 👍

LONG TALL SKINNY CAST BLOCK AND HEAD. SMALL RADIATOR. SMALL GRILL OPENINGS TOO NOT ALLOW GOOD AIR FLOW. THE EVER SHRINKING ENGINE BAY SIZE THAT HOLDS HEAT . THIS HEAT ISSUE STARTED IN THE EARLY 70S WITH 6 CYLINDER ENGINES. SOME MAKES AND MODLE YEARS GOT BETTER SO NOT SO MUCH. STRAIGHT 6 CYLINDER MOTORS NEED REALY GOOD AIR FLOW AROUND THE AROUND THE OUTSIDE OF THE BLOCK TO START WITH. ME I LOVE A BUILT AMC 258. FORD 3OO. CHYSLER /jeep 4.0. JUST SOMeTHING I OBSERVED WORKING ON ALOT DIFFERNT RIGS FROM THE 50S TOO THE LATE 90S. EVERY DECADE GETS WORSE WITH HEAT SOAK. SAME APPLYS TOO TRACTORS AFTER THEY STARTED PUTTING ON THE SIDE METAL PANNELS AROUND THE BLOCK.70S ISH. JUST BECAUSE ITS STYLISH DONT MAKE IT EFFICENT . CHEVY WAS THE FIRST TOO FIGURE THIS OUT AND DID AWAY WITH THEIR STRAIGHT SIX FOR THE SMALL 232V6 ? STARTING IN THE MID 70S IN CARS AND 82 ? IN THEIR TRUCKS. Sucks too because they built some dam good straight 6 cyl engines in their days.

Mine never overheats I think they were meant to run at 2:10

Отличная тачка 👍

Engines run best at 210f. for smog and emission laws. Put it on a dyno. Guaranteed she makes more power at 180-200f temps. Nevertheless this will lower gas mileage.

An aluminum radiator will solve your overheating problems, put one in my 91 cherokee. I can drive up long drawnout hills and never reach 210 degrees.

Mistake #1 - buying a jeep (jk jk, love the build)

Bro takes 3 mins to tell us he doesn’t have a 4.0 in his shit lol

I just can’t stand the sound of a diesel . But definitely a sweet build looks good to

Cherokees do alot of weird Chrysler sh#+. I never had or seen one overheat. 🧐🤳🏾 i lived in the Desert too. I don't even look at my gages anymore.

Why the fuuuuuck you running monster tires on a 4 LTR ?

420th like

This is blasphemous.

One cure might be to stay off Facebook. Both of my 01's run just a shade above 200 and have for years.

Cool that you brought that shit box out to the beach …..