Why Does The Jeep 4.0L Overheat?

In this video I will be going over the entire cooling system on a Jeep 4.0 and fixing an overheating issue. This process is similar on other Jeep models such as the Grand Cherokee, Wrangler, and Comanche. But today I will show you the process on a 1997-2001 Jeep Cherokee XJ. If you have any other questions that the video doesn't cover make sure to comment below and I would be happy to answer.
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Purchase a Jeep XJ Fan Here: www.amazon.com/gp/product/B00...
Music used in this video:
Stomping Grounds by Silent Partner
Pickup Truck by Silent Partner

[@KaidoFujimi]

2001 XJ Limited owner here. You're SPOT on with everything mentioned. Thanks for giving aid to keeping these ol' bricks rolling.

[@georgecurtis6463]

I bought a 96 Cherokee new. Within a year I had gone up to the sierras to explore some fire roads. It was about 85 up there. As I was climbing a long upwards grade road that I would rate mild for a jeep, I noticed the temp climbing towards overheating. Was a bit surprised by that so I turned the ac off and turned the heater on and that cooled it down enough. Got to our destination,and let it idle for a bit then shut it off and opened the hood. After that on our way back all was well. But i just never got back to figuring why it got so hot since i didnt think it was working that hard. Anyways, when i went offroad i just turned the ac off. Unfortunately i got into an accident caused by the other driver that caused me to become a paraplegic. Sold the jeep to my bill. Loved that jeep and it was always offroad on the weekends. Anyway, now i have an idea what to do the next time !

[@bret7306]

Austin, Bro! This is the BEST cooling system video on the net. I have been watching vehicle repair videos for years. I have to say you are great at telling the What, Why, and How. That is what people look for when watching repair videos. None of the "this thing" or "that right there". Your explanations are simple and to the point. Your repair process is methodical, step-by-step, and detailed. Showing the tab slots for the electric fan is an example. Most vids would not show it, but you know someone out there is wanting to know what you were talking about. Very well done young man, keep it up. I will be buying an XJ for a project and will follow your channel for insight and information.

[@OutJeeping]

Glad I could help!

[@KeithCars]

The more videos you post, the more I realize is wrong with my XJ! Really appreciate the good info.

[@SCscoutguy]

You can also test your electric fan by just turning on the defrost. It always runs when the defrost is engaged.

[@Bonobo277]

Thank you for this tip! Was wondering how to do a good test on it.

[@SCscoutguy]

@@Bonobo277 You are welcome. It is a pretty easy way to test it without having to open the fuse box.

[@SCscoutguy]

@DJ B It does not run 100% of the time when the AC clutch is engaged. It will be on most of the time however depending on engine temp.

[@Gordon013]

That doesn't work in the 00 and 01 models. They changed it so the fan only turns on once it gets to a certain temp.

[@Gordon013]

@Dean Bennett I only found out the hard way by thinking my electric fan was broken when the AC was on since I was used to it always being on in my older XJs.

[@wvtrails4103]

Great video. Can’t thank you enough. I found my electrical connection from fan to harness causing the fan not to come on. One of the male ends was not inserted properly into the female end, causing and improper connection. You saved me the cost of the fan and labor. Thanks buddy. Keep up the good work.

[@moabwheeling]

Very well explained !! I have watched some of your past videos and i like them . Just subscribed to your channel . Keep up the great work .

[@Shawncsc]

Super informative video. I'm redoing the entire cooling system on my 97 xj. The guy before me used some of the worst aftermarket parts I've ever seen. This was a great run through. Thanks brother

[@TheRussianWookie]

Great video!! Extremely informative. My 99’ Jeep runs super hot in this 90 degree weather.

[@randomcitizen2384]

Last week it was 115 degrees here in the Phoenix valley. It was probably closer to 130-140 on the asphalt sitting in traffic. My 1999 XJ with the stock set up stayed around 210-215 while sitting in traffic. I have replaced the thermostat. E-fan and flushed the system within the last year. It all works well and the AC is always cold. If I hade the room I would have a whole field full of XJs.

[@todhollo1961]

I am filling my ten acres with them just got a 2 door and a pickup along with my 93, plan to get more

[@randomcitizen2384]

Tod Hollo It’s like a game preserve for endangered machinery! God speed to you!

[@OutJeeping]

I'm glad I've never experience heat like that before lol. But at that point the Jeep is doing the best it can on Cooling, it probably wasn't designed to take on that kind of heat every single day. But if I lived in that environment I would have to modify the cooling system a little bit or even add hood vents to have all that hot air escape.

[@randomcitizen2384]

OutJeeping I am conflicted about hood vents. If the engineers knew best why did it not come with vents? Having rain on the electronics seems like a bad idea. However I do see how it can help with the heat. To vent or not to vent? That is the question.

[@frankmick8683]

Im in Phx as well. These past two weeks I've not been driving the XJ (2000) because it runs at 210 and gets real bad heat soak when I stop at a store or something.

[@MichaelWalkerWV2SC]

I have a Jeep Wrangler 4.6 l Stroker. The extra power generates even more heat and it seems to be trapped in the engine compartment especially in traffic. I replaced the radiator with an aluminum 4 core radiator thinking doubling the number of cores would fix the problem of running about 205 degrees. It didn't, so I bought a louver attachment for the hood and cut out the areas of the hood under the 68 louvers which allow air to escape. The hardest part was the measuring and cutting holes in the hood to make it look like it came that way. It runs at 180 degrees everywhere now, as if the hood was off the Jeep leaving the engine compartment open. The matte black powder coating makes the hood attachment look pretty cool also.

[@robertbryant7771]

Very good series of videos, thanks for sharing your time on it. One small correction on the older 4.0s is from 87-88 there is a temp sender for the idiot light or gauge, depending on cluster. That grounds on the head where it’s mounted at the rear corner, driver’s side, and a single post out to the gauge/ light. There also is the temp sender, 2 wire in the block below the intake near the knock sensor that goes to the ECM. One wire is ECM sensor ground and the other is signal to ECM. In 89 they moved the ECM sender to the t-stat housing and kept the gauge/ light sender on the back of the head. These engines through 89-90 had a thermal switch in the radiator to close the electric fan circuit’s relay. With the HO from 91-95 that switch was no longer needed, as the sender in the t-stat housing allowed the ECM to calculate fueling and electric fan control with the value from a single input, whereas before the electric fan wasn’t controlled by the ECM, just a simple thermal switch. And of course 91 was the start of the open cooling system so the radiator changed to add a cap and over flow line and omitted the fan control switch. 96-01 saw changes to the ECM and possibly a couple changes to wiring but the gauge/ light sender remained in the back of the head and the ECM temp input in the t-stat housing

[@garyhowell738]

Not so fun fact, the reason the XJ runs so hot is due to the 4.0 wasn't intended to be an option for the XJ. The cooling system was designed for the 2.5.

[@OutJeeping]

You are correct!

[@j.d.mcginn6946]

I totally agree with you. I took out my stock radiator and fan clutch and I realized that, with minimal trimming with grinder and dremel - one can fit a 18" x 18" x 3" all aluminum radiator with a 16" fan and still retain the ac condenser- which i fitted 2 smaller fans i front of the ac condenser (come on when the ac is turned on) for even more air flow. With this setup I got 170 water temp under 90 degrees. Above that it went to max of 215 in 110 degree weather. So, i cut into the hood with the large hyline vents so can't wait till next year to see if it lowers the 215 in 110 weather. I live in mostly dry desert. Prob wouldn't cut the vents in Louisiana but the vents don't really make it wetter then before. At 70 mph rain would cover the entire engine from the holes in the grille.

[@gregwendt7172]

What parts of the cooling system are inadequate?

[@julianlord2697]

@@gregwendt7172stock there is no inadequacy but it is marginal. The clutch on the mechanical fan loses its ability to transfer power, the radiator starts to clog, the coolant gets old. It is also possible to have a fault such as a weakened pressure cap or leaking core plugs etc. I run all day in 40 degrees celcius and it can run fine when maintained but worn fan clutches etc can creep up on you.

[@gregwendt7172]

@@julianlord2697 Thanks for replying. I've tested everything (fan clutch.etc.). The coolant is new and there is no leking from the block, etc. The radiator is clean and it's an aftermarket 3-row aluminum welded performance unit. The heater core was plugged but was backflushed until clean. I replaced the heater hoses and ran them away from the engine and around the fender wells. They are longer this way and allow for a slight increase in total coolant capacity. I was a mechanic for quite a few years and solved many overheating problems but nothing has worked, so far, on this jeep. the clutch fan and the electric fan work according to specs. I replaced the cap and it has the appropriate spring pressure. I'm currently shopping for a new radiator and it will be a higher capacity 4-row type. This way, I'll be able to choose the fin spacing and tube size for the best cooling. It doesn't overheat often but I want it even better.

[@bobbynate4271]

Very good work sir. I would recommend Hi-tac for gaskets. It makes installation very easy and unlike RTV it can be cleaned with solvents. Especially if you have an irregular mating surface. Plus squeeze out doesn't contaminate the system.

[@jake-mv5oi]

Agree with everything you said. Tried the CSF 3 row and it didn't cool any better. Sprung a leak after 2 or 3 years and I replaced it with stock style. ZJ fan clutch was the best upgrade I've done to keep it cool. I used a flowkooler water pump and had no problems for 10 years or so. Parts store pumps just didn't hold up.

[@gregj.gotham4402]

Great video very good explanation of the entire heating cooling system including how to test. Thanks for all the info.

[@lacherokeedecaceria1263]

My 1997 XJ stays around the 190-205 degree temperature, all I did was install a new radiator, new fan clutch and new thermostat with a 1/8’ hole drilled on top. Zero overheating issues even in traffic and I live in Tucson and summer temps are around 108’ and also while on the trail.

[@shanemunoz5691]

I learned a lot ! I always wondered why my passenger floor was wet 🤣

[@danhambrick6331]

Nicely done Austin....

[@andrewdobson1783]

Really thorough and to the point. A great video!

[@zxej6879]

Most vehicles today have only a 2 row radiator core. I have had vehicles that I upgraded to a 3 or 4 row radiator core. That gave excellent results for towing and offroad. Another trick is ceramic thermal barrier coatings on the exhaust manifold or headers. My '03 Ford Explorer 4wd has ceramic coated JBA shorty headers. When I take it in for a California smog inspection. They lift the hood, and think the engine is cold. They hook up to the OBD2 port. And find the engine is warm. I plan on buying the ceramic coated headers for my '96 Jeep ZJ.

[@ProjectDanH]

Great vid as always 💪

[@gshock3092]

I run 180 in my xj. And it did help it run a little cooler!

[@kazuza9]

U did a good job on this video. Very detailed explanation

[@dalebailey1844]

thank you and HAVE A GREAT DAY!

[@fmartino100]

Great video lots of fun to watch...

[@timothysimpson912]

I love your channel! So helpful.

[@alankatterheinrich8660]

Thanks for the video. I'm about to start this in the next 10 minutes.

[@salamefamily6232]

Best detailed video everytime!

[@Rob_P80]

Great video. The cooling system is the first project i am working on. I replaced the radiator/hoses, & water pump. I have the thermostat and housing i need to replace. i got my 99 with the electric fan missing completely... so i need to get one of those too soon.

[@erik6134]

Thanks from Ensenada México 👍🏾👍🏾

[@muhsinaziz920]

Very informative, thanks mate !

[@MICHAELWALTON1]

NP you answered my question. Good instructions! Thx

[@99jeepxjguy97]

Wow! Did you say that red XJ had 300,000 miles? Looks very well maintained for those miles. But I suppose that is why it has 300,000 on it. Just wanted to back up ToneDeaf on the spring clamps being a better system than the worm gear ones. Great video. Well put together. Thank you!

[@verbaldavenci1]

I installed a 36amp fan in my jeep 4.0 and it stays nice and cool. The stock one that I took out with a 9 amp huge difference☺

[@luisbarraza9709]

Any mods required? Mind sharing a link?

[@verbaldavenci1]

@@luisbarraza9709 I went to O'Reilly's and bought 36amp cooling fan it wasn't specifically for a Jeep I just wanted something with some power and I just hardwired it directly in fortunately for me there was already a 40 amp fuse under the hood in the fuse box so it worked out pretty good.

[@lucaswest5365]

I had a friend that bypassed his ac compressor and and swapped his trans fluid lines to the ac condenser and plugged the old holes in the radiator with brass fittings and it helped tremendously

[@kleyvertmartinez6400]

Very good info!!

[@bjrnhjjakobsen2174]

Nice video as always - still waiting for a heater core replacement video😂

[@RC_Cubed]

I second the heater core video. On my to-do list this fall.

[@slant6guy]

The 2003 Jeep TJ Wrangler AMC 4.0L w/o electric fans here has never overheated except when the wrong length serpentine belt, for the aftermarket Eaton M62 supercharger, slipped off at 65mph and shredded to pieces. Had to guesstimate a replacement belt size after walking several miles to the auto parts store...fun stuff.

[@jaymase3735]

Make sure all hoses, radiator, shroud, thermostat, radiator cap, water pump, fan clutch, and electric fan are functional and in good shape. Make sure your fluid is good, bled properly, and at the correct level. If you do all this and the engine isn't broken, you will not have cooling issues. I live in Tucson, AZ and it gets extremely hot. I drive a '92 Comanche as a daily driver and company vehicle for my business. I never have any issues cooling, even with the A/C on Max, in traffic, in the summer when it's 115° outside.

[@directionallycorrect2027]

Great video. Thanks!

[@stevenm7566]

This guy is a great instructor. Subscribe!!

[@bobwells3184]

Great video!!!

[@drgil65]

Great video, Thanks

[@elev8j10]

I find having the auxiliary fan on a manual switch and a little lower temp thermostat for the summer works well. Still stays about 195 with the ac on in a 100 degree day. I just switch back to a higher thermostat in the winter. I do have a little more capacity in my radiator than stock. Heat wrapping the headers down to the y pipe is also a good modification. Helps limit heat soak and keeps the trans and transfercase a bit cooler. Later 4.0's had a heat shield under the fuel rail which you can use in any older 4.0. Just be careful not to let it run too cool though.

[@lawrencemaxwell6536]

manual elec fan switch, 180 therm and took off heat shield junk for better airflow around manifold side......let fan run minute or two b4 /after running on hot days or sitting in traffic or drive thru works great

[@surfferb]

Good job man.

[@TeddyUsick93]

Installed the exact same fan a week ago. Had a hard time getting the fan out as the one clip on the right side was really hard to get at. When we got it out we ended up actually braking off the clip on the old fan. Installed the new fan on easily but I actually still haven't tested it to see if it is kicking on as I was waiting to check when the temperature went up. Going to try one of your methods. Was told it was a bad electric fan from my mechanic as I was having overheating problems and the radiator I had put in from last December was still under warranty. I drive a 2000 Cherokee sport. My Dad loves the Cherokee's so much he went out and got a 2000 Cherokee limited as his main vehicle now. Thanks for the great video!

[@OutJeeping]

Thanks for watching! Yeah over time that metal lower clip gets rusty and can be a pain to get out, that's what happend to this Jeep on one of the previous times I removed the fan.

[@rickhenninger6978]

Great video

[@prestondallas4035]

I have a 98 XJ with, as of today, 307,002 miles on it and I have had it as my daily driver for over 3 yrs and it hasn't over heated once. And it's sad to say that I have never changed or flushed out the coolant system nor have I added any anti-freeze I also would not be surprised to find out that it's probably the original transmission fluid 4.0 straight-6 rules! JS LOL

[@JohnDavis-ss4dw]

The spring hose clamps are designed to expand and contract with the different Temperatures of the engine coolant.

[@deanwattles8722]

fan shroud and clean cooling system.......no problems, in the trails or traffic

[@elsydeon666]

IIRC, the fan kicks on at 195. It'll also kick on if the front temp sensor is disconnected. You can also get rid of the diaper under the engine, which is probably a oil-soaked fire hazard by now.

[@mrkultra1655]

Nice one, thanks

[@charlieswearingen500]

I have a '96 High Output 4.0 and solved my overheating problem with a high-performance thermostat. I also used an air grinder to grind out the interior of the water thermostat housing. That removed any sharp angles and enlarged the interior of the housing to make it smooth out the flow of coolant. My coolant temps dropped considerably...

[@99jeepxjguy97]

Hmm . . . Interesting. I hadn't considered the deburring of the housing.

[@georgecurtis6463]

Just a note from a retired mech. When checking things as a fan as you did, it's best to check the whole system, starting at the sensor and the fuse. This way you dont get other surprises.

[@user-pd1jn1cz2g]

Good job

[@user-pd1jn1cz2g]

I love this channel because I learn from it everything new and useful

[@Mauser1965]

Not sure if you reviewed this prior to it's release, but are you aware that you were pointing out to things out of camera angle. Though the lighting, shooting clarity and audio was spot on for a video tutorial. I personally like the closed loop that's currently on the '89 XJ I've been working on the cooling system is much easier to fill than all the various open systems I've worked on thus far. Great work thus far and I hope you are able to keep releasing as much as you can over time, thank you.

[@benforshee6269]

I put a mechanical fan in with the electric fan and it's now sitting around 190 in mine. I also installed a trans cooler.

[@Miniscapes515]

You actually want spring style clamps on radiator hoses. Because of thermal dynamics the rubber hoses and plastic radiator necks can shrink and expand depending on ambient tempatures. Spring clamp allows it to maintain the same clamping pressure as it shrinks or expands and not cause leaks.

[@99jeepxjguy97]

Yes, I caught that too. The old urban myth about factory spring clamps being bad ! . .. . The other advantage of the spring clamps is that there is fully circumferential clamping.

[@philipoien7562]

Right! Screw-type clamps don't tighten themselves. Just as the video author says several times, the engineers knew what they were doing. The only caveat being the clamp may get tired. A tired clamp does not mean you replace it with an inferior clamp. Stick with the factory style clamps, and healthy hoses that are not all compressed where the clamps go. Hoses and clamps are inexpensive preventative maintenance.

[@MiguelGarcia-vj7oo]

​@@99jeepxjguy97 spring clamps are the best..... project farm did a test on all automotive clamps and those were the best.

[@99jeepxjguy97]

@@MiguelGarcia-vj7oo Yes, I agree that spring clamps are the best.. I have known this for years. I did not know project farm had done a test, however.

[@lpd1snipe]

I recently picked up a 97 Wrangler TJ. It was purchased by a friend of mine from his deceased friend to help the wife pay bills. Long story short it sat in his backyard for several years and it didn't have coolant in it just water. The clutch on the fan was working okay. When I got it it, was full of rust, full of crud. I had to flush the heater core. I ended up replacing the radiator, the water pump and I went to 160° thermostat. Now it actually will maintain temperature without overheating. But what a pain in the butt when people don't use antifreeze.

[@gero195]

I live in Texas ,auto transmission sucks and heats up rad temps so I slapped a bnm with temp sensor transmission stays under 200° out of the torque converter , but in cold temps cardboard on the grill is my fix lol

[@DoodlyDoo59210]

I finally replaced my water pump and that seemed to do most of it. The weep hole was trickling and I didn't know where it was coming from, and then one day it was literally pouring out of the large lower weep hole. Another issue I have with my AC is the compressor seems slightly difficult to turn adding a load to my belt system. Running the AC in town with stop lights and stuff make my air come out hot and sometimes overheat the engine. I haven't had overheating issues since I replaced the water pump.

[@BallisticBBQ]

Great video! The engineers did know what they were doing, but remember this engine bay was designed for the smaller 2.5 L and 2.8 L engines. The 4.0 L sits too high and crowds the engine bay. I have a very built-out XJ and I tow an off-road trailer. Stock cooling just doesn't cut the cake at all for me. The best improvement I made was going to a Novak single core radiator with 1.5" tubing inside, combined with 3 electric fans. I relocated the transmission cooler (away from the radiator) and added an engine cooler (also away from the radiator) and my problems are 100% solved. Even taking grades with the AC running! Thanks again for the very detailed video!

[@PiggyDetector]

My Jeep kept sitting at 200° and then I realized it didn’t have a fan shroud. Threw one on and it dropped my temps from 200 down to 185-190

[@grahamburgdorf8397]

It's supposed to run at 190-220°f

[@blainflake9835]

Graham Burgdorf exactly right. Factory thermostat =195.

[@AWBepi]

Fan clutch...even if you think yours is good, if you are over heating replace it. My normal op temp was the half way mark...after a fan clutch its now operates at the 1/4 mark and only gets to the half mark when hot it traffic. DO IT!!!!!

[@afed24]

Should do some reading on constant tension spring clamps on cooling hoses(the clamps from the factory) they’re actually better then those aftermarket worm gear style clamps. They keep constant tension on degrading and hot/cold hoses to prevent coolant leaks in temperature changes. They’re better then those worm gear clamps that hold 1 pressure on the hose all the time. As condition of the hose changes by expanding/contracting or degrading the clamps keep constant even pressure. Just like everything else on XJ’s they used those for a reason. There are aftermarket constant tension clamps you can purchase that are easier to use like a worm gear style clamp that work well.

[@99jeepxjguy97]

Agreed. The old urban myth about the spring clamps just won't die!

[@Jeeptalkshow]

Cool tip, pun intended, about disconnecting the coolant sensor. I just turn A/C on and efan comes on, if it doesn't it's bad, or not getting power.

[@rodrigohuallanca662]

Awesome.

[@timcrump1810]

I put a mechanical fan from an older jeep. Just make sure you have the old style water pump with the threaded shaft.

[@huathai8204]

Did clean the inside of the cooling system on my Jeep Wrangler 4.0 with evaporust. I had a light rust problem that showed up after a flush. Cools it like an iceberg since it did it.

[@scottbollinger3999]

@ hua Thai - I never thought of this. How long did you allow the evaporust to sit in there before you flushed it? Can anyone think of a reason this wouldn’t be a good idea?

[@huathai8204]

@@scottbollinger3999Empty the system out, put it in, fill it up with just regular tap water. Put the cap on the radiator and did a 200 miles road trip. It works best when hot. Flush it out immediately afterwards. Re did the flush with distilled water and anti freeze and done. Did it 3 years ago and still no problem so far. When you flush it out the water is dirty black.

[@scottbollinger3999]

@@huathai8204 it’s an iron block so that makes perfect sense. I’ve used evaporust on other things and never thought of this. I guess I’d just be afraid of it dislodging flakes or whatever and blocking passages but I guess that could happen at anytime

[@cameronferguson8236]

I would recommend using the spring in that lower hose. Even the new ones can get hot and collapse.

[@RcH382]

I have 2 cherokee sports with 4.0 and a 318 gr cherokee limited. I flush the engines as the cast iron blocks rust a lot inside. on the 2001 i used 911 rust dissolver in the motor. It mixes with water and i let it sit for weeks starting occasionally. It removes most of the rust. New 3 core aluminum racing radiators for about 110$ New aftermarket water pumps, 50$ and a 180 thermostat always. 195's are just too hot, period. they are there by the manufacturer for emissions only. I highly recommend using an occasional good injector cleaner and Gunk carbon cleaner is a must. Using a borescope i can see the shiny piston domes and the idle smooths out on start up. The serpentine belts will chirp and squeal on start up and warm up if you don't tighten the belt quite a lot. Best suv ever and i am proud to drive my 2000 every day. It is my most reliable vehicle and a lot cooler than all the other more modern suv's.

[@kelvinstrickland7442]

I just replaced the radiator in my 2002 Jeep Grand Cherokee Laredo brand new $220 Canadian and its perfect and the air is ice cold and was worth going new for the price new.Great Vedeo .

[@thatairplaneguy]

My 01 has never overheated. If you have your stock shroud, the clutch works and the electric fan works it should never overheat. I can crawl all day with the AC on in the hot Kentucky summer and it doesn’t overheat. Now it did heat soak the fuel rail until I added hood spacers but now after 3/4” spacers that is fixed as well.

[@todhollo1961]

My 93 never over heats, the reason for the 190 degree thermostat is if run cooler would not pass smog and engine compartment was only ment for a 4 cyl engine. I also hole in cowl to let out engine bay heat...

[@twinturbo7234]

Look for a bigger fan clutch that fits your fan/ jeep , a lot more air.

[@larrybradford5092]

if you are using a molded lower radiator hose it must have spring inside the hose . or use universal hose that the spring is molded into the hose.

[@charliedee9276]

Vent the hood. The problem starts with a large engine in relation to the bay it sits in along with the unibody design which provides no gap between the body and frame. This is the root cause of the problem, air cannot escape the engine bay as readily as it is pulled in by the fan(s). If the air on the engine side of radiator cannot escape air will not flow through the radiator from outside no matter how much the fan is pulling. It's simple displacement of the air, the only way air can easily come in an enclosed area is if the air already in the enclosure has an easy way out. When I lived in the Arizona desert the trick was to space the back of the hood at the cowl up and remove the cowl/hood seal, or just cut a couple holes in the hood and put a return air furnace vent over it. My current Jeep Grand Cherokee WJ suffered the same problem, 4.7 V8 stuffed in a small hole with no easy air egress. Venting the hood reduced the under hood temp by about 30 degrees in the summer trail running with AC running and dropped the coolant temp from around 205 to around 195 which is the temp of the thermostat opening. Sitting at idle with the fan running I cannot keep my hand over the vents, there is a substantial amount of air coming out and it is HOT!

[@luisbarraza9709]

Fingers crossed this works, I just ordered some hood blocks to vent the hood.

[@charliedee9276]

@@luisbarraza9709 find a plastic bottle, and put a small hole in the bottom of it. Fill it up with water holding your finger over the hole. Turn it upside down and let the water drain out with your finger still over the hole. Notice how slow it dribbles out. Now release your finger and watch it flow out very quickly. It is a very graphic demonstration of what I mean about air in and air out.

[@wirebrush]

I believe this is the correct answer. It's no coincidence that Jeep vented the hood when they put the high output 360 in the 5.9 Grand Cherokee. This also explains why it's a known issue in the XJ and not in the YJ, TJ, and ZJ with the same engine and components.

[@keithlucas6260]

If you watch Matt's Recovery Towing videos, he did this to the "Banana" XJ. He has a video explaining how he fixed the overheating issues.

[@x1carrier]

That is exactly what I did, I cut two vent spaces out of my 2004 Grand Cherokee (with the 4.0) hood, then installed stainless steel vents with hood scoops over both sides. Never had an overheating problem again. And I did that 7 years ago.

[@SantanderDiogenes]

Excelent video!! Wery well explained and resumed. I have a problem with my Cherokee that tends to overheat in hard traffic. I have found that the electric fan turns on when the motor is already averheated. I have replaced the Coolant Temperature Sensor mentioned in the video, but the problem persists. I have found there are sensors with different Temperature-Resistance performance. Could anyone tell me where I can find an online store where I can buy the right one for a 1994 Cherokee model?

[@OutJeeping]

Double check and make sure you don't have 2 temp sensors. One could be on the back of the head and the other by the thermostat. Some years had 2 sensors, one for the gauge and other for the fan. I would stick with factory styles of sensors and not change it up to anything aftermarket.

[@kenburns4551]

If after checking all that and your over heating still. maybe it’s your transmission shift solenoid. I have a problem with it constantly downshifting at freeway speeds or going up hill. Regular in town driving is no problem.

[@madmacc040]

FYI - OEM spring/constant tension clamps are the best. The key is constant tension at all temperatures(expansion/contraction). If the clamp is removed or disturbed, it is crucial that the clamp is positioned the exact orientation/location as before. In the exact indentation made on the hose by the clamp or it will leak.

[@OutJeeping]

I agree with that. I've had a coolant leak one time when it was -15F. But reason I don't replace them with the original clamps is due to the poor condition they are in and not always easily available to get compared to a traditional hose clamps.

[@Gemini_901]

I have a 2002 Jeep Grand Cherokee in my fan won’t come on when I turn my ac on, in my ac clutch fuse don’t turn on my ac too, but when I by pass the fuse it comes on? I need help please.. Can you help me??

[@ibberman]

11:48 Interesting, the water pumps for my 93 XJ 4.0 and 2004 WJ say reverse rotation on the Napa parts site.

[@OutJeeping]

Depends on year of vehicle due to belt routing.

[@starliteaquatics7308]

Man I was rolling down the road Boom Fan Exsploded guess it had enough heat cycles even on a cool morning luckily didn't fuck anything up like hoses or belts 😬 got another one ordered seems to run fine without but getting a new one just incase ... side note my 2000 I had wj didn't even have one just a clutch fan

[@jesusyuca1483]

I never had issues like not enough air flow or capacity. I have an older style with a single belt driven fan. My real issue was lag of the thermostat opening caused by the design of the thermostat housing itself and the fact it’s in front of a huge single fan. The thermostat housing would cool down so much from the air hitting it directly the thermostat would lag to open. This especially happened when I installed a lower temp 180 thermostat. How I solved it? First off if you do this, it’s at your own risk. I live in the Caribbean so no cold weather for me. This works for me and I haven’t needed to touch the coolant in over 2 years. Remove (cut off) the little piece of metal that blocks a little hole in the thermostat. This allows a little coolant to always pass by the thermostat allowing the thermostat to heat up much more quickly eliminating the lag. I honestly believe the best way is to insulate the thermostat housing but that’s something I haven’t tested.

[@blainflake9835]

Or drill a tiny hole in the tstat

[@loganjames4607]

I live in AZ and my thermostat on my TJ was stuck closed. The Jeep only survived for the previous owner on brief drives by using that one little thermostat bypass hole. Crazy that he limped it around and only drove it in the winter instead of investigating the problem. Glad he didn't crack the head in the process.

[@ian_s9382]

I ordered a different one that was more expensive, how did this one hold up?

[@sharonsatterwhite1180]

I've got the opposite problem. '93 grand Cherokee L4. I can't get it UP to temp. New W pump, therm. radiator. Rarely gets up to 200...in Arizona...in the summer!

[@OutJeeping]

It could be a faulty temp sensor reading incorrect values.

[@georgemullin7772]

Removing my clutch fan for San electric fan with switch

[@tna2me197]

My temperature gauge seems to be running in the 200 to 210 range. So you're saying that is ok? Seemed kind of hot to me.

[@simonsays582]

Get some hood scoops. 👍

[@Deadbuck73]

Should the mechanical fan be kinda stiff to turn by hand?

[@gage9163]

Mines black on 31s and I do a solid 90+ on the highway and have never overheated

[@generalsiv4747]

My electric fan doesn’t kick on when past 210. I’ve tested the fan and works fine. Relay works and the temp sensor has been replaced 3 times so I’m starting to think it’s a computer related problem. Any ideas on what I should do? I’m planning on getting a external auto temp switch.

[@OutJeeping]

It should kick on around 220 if everything is working properly.

[@MoparMan-ff8fb]

Installed an after market electric thermostate sensor from jegs that can be adjusted .its dial turns for differnt temps settings to kick the electric fan on . we by passed the factory coolant sensor that kicks the fan on. we have it set to 180 ° for the summer . have you tried the after market company Moroso ? they sell a kit with 3 differnt colored anodized flat washers with difernt size hole in the middle of them. they replace a factory thermostat for better flow and cooling . also VP racing fuel also offers a bottle of additive at oreallys that drops the coolant temps by 30°. stay away from the cheap shitty thermostats from oreallys and autozone . STANT brand thermostats are great and made in America

[@ilmjcxj8064]

How good is aftermarket electric fans for the XJ in terms of pulling the right amount of air (CFM)? I've had a bad experience with an electric fan in the past (I don't remember the brand). It didn't fail, but was not pulling enough air to keep the system cool on my 2000 4.0L XJ in the Summer. That's why I replaced it with an OEM one, even through was very expensive.

[@OutJeeping]

Honestly there are so many aftermarket fans on the market, it's hard as to tell which is good and not-so-good, you mostly just have to go off of other people's reviews. I'm not sure on the correct number for CFM that's needed keep the Jeep cool. A lot of people take out the factory fan setup in Run 3 electric fans instead, which is not a bad option. But you just need to make sure to have a correct fan relay setup to have certain fans turn on at certain temperatures, and for the fans to be drawing enough air. If it were me and I was going to that setup I would compare the CFM from the new fans to the factory electric fan and try to get it close if not better.

[@jeepoutlander717]

2400 CFM in total, 3 electric fans of 800 CFM each Shroud has to be minimum just enought to support fans. If shroud is solid with only openings for fans it restricts airflow. Connect all of them running at the same time for best result in hot climates.

[@joesanchez3646]

My 2001 fan relay failed and it did give me a warning, a week before it failed the fan stayed running after I turn off the engine, I had to unplug the fan and plug it back in and it ran normal, a week later it failed, 2: at a 160,000 miles the electric fan “ blades “ broke apart, I thought the driver ran over a piece of hard plastic, 3: also on the 4.0 the #1and #6 spark plugs are fired by the same coil, when the check engine light flashes and you can smell raw gas coming from the tail pipe change out the coil pack😎

[@sevensinsvelocityshop7563]

You actually have your upper and lower hoses backwards, lower comes directly off the water pump, lower feeds the radiator upper feeds the engine through the thermostat

[@0hn0haha]

Tbh I've literally never had overheating issues. I do most of my wheeling in early winter tho

[@jrreynolds5290]

Trying to get a 98 Cherokee classic up and running. Relay in fuse box is good. Flushed the system twice. Replaced the water pump and well as the coolant temp sensor. AC is not working as well as the electric fan. Any suggestion would be welcome.

[@OutJeeping]

Have you tested the fan by hot wiring it?

[@jrreynolds5290]

Yes the e fan as well ac work with power from a test light. Relays in box are good. Have moved them around to test.

[@OutJeeping]

@@jrreynolds5290 Well the fan should kick on around 220 and should be on with the AC. Do you have enough refrigerant in the ac system? It won't turn on if the pressure is too low and too high.

[@4tcfilm]

Great video, question about coolant: is it orange better than green one?

[@OutJeeping]

Green is what is recommended for this jeep. Other cars require different colors because of the chemical composition of what is inside to help protect the cooling system. Orange helps if protect aluminum parts a little better from corrosion.