Diagnosing and Fixing Overheating Issues in Jeep JK - Thermostat removal and coolant flush

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Diagnosing and Fixing Overheating Issues in Jeep JK - Thermostat removal and coolant flush

Рет қаралды 30,000

2 жыл бұрын

*UPDATE* This video left off with a “i hope this fixes my problem”. So i wanted to report that this did fix my issue. I have not had abnormal temperatures since i replaced the thermostat and flushed the coolant.
Last November I started experiencing overheating issues after a trail run in Northern Virginia. I cleaned my radiator and engine bay to clear out all the built up mud, and while driving under regular conditions, my temperature was maintaining, however it was running a little hotter than normal. At highway speeds on steep hills or long drives my engine would overheat and I would be limited to 45mph, or have to keep my RPMs under 2500.
I checked what I could on the water pump without removing it, and have no indications that it's bad. So for today I decided to remove the old thermostat and install a new one, and do a full system coolant flush to make sure I get any contaminated or old fluid out.
#4x4 #jeeplife #offroad

Пікірлер: 119

@dougel4709 Жыл бұрын

Thanks for the video! You just helped me change my thermostat.

@bigzoffroad Жыл бұрын

Thankfully this engine is super easy and accessible for the thermostat!

@scark00 11 ай бұрын

I have flushed and filled my system twice and I'm on my 4th thermostat. I've burped and I've bled but the issue keeps coming back. I recently read that the 3.6 engine has an issue with fine casting residue that is clogging radiator and taking out thermostats. I've only read about this but from what I'm seeing I believe it. 2016 JK with 70k on it.

@bigzoffroad 11 ай бұрын

I’ve not heard of that issue.

@Steve-zq8ge 11 ай бұрын

Same boat as you man. Got a 2015 Willy and super over it.

@billgraham3175 Жыл бұрын

One thing you can not forget to do is use the bleeder located on the thermostat housing. Open it up while filling the radiator when coolant comes out close it. You will get an air pocket in the housing, also park at a slight angle (front end a little higher) to help the air move to the highest point. Thanx for the video.

@bigzoffroad Жыл бұрын

So, i didn’t open the bleeder, and did not have that issue. Also yes! Where my Jeep was when burping the system is at a pretty good angle 👌

@bigzoffroad Жыл бұрын

But i was wondering about the bleeding valve. I know how to use it, I’ve used it when i didnt have the radiator funnel available. But is it necessary if you do it the way i did? I haven’t had any issues, can’t really CONFIRM that i dont have air in my system… but I’m pretty sure i don’t. Wasnt able to get any more out.

@billgraham3175 Жыл бұрын

There's always more than one way to do this. I have many Jeeps that still have air in the thermostat housing even after completing as you did. You said that you did have it parked at a slight angle which also is important. You could have good luck using this method, until you don't. I now use a method of vacuum pressure that sucks the coolant back in the system. It's quick and no mess. Thanx for your video..

@bigzoffroad Жыл бұрын

@@billgraham3175 that vacuum method require some special equipment? Also, I’m gonna run it through again and use that bleeder valve on the thermo housing and see if i get anything more out! Thanks again!!

@billgraham3175 Жыл бұрын

No special equipment just an air compressor and I use the Astro 78585 set-up it really works well. It's a bit pricey but it works on lots of vehicles.

@tylermitchell1990 Жыл бұрын

5:20 Ah, yes I can hear the air. 5:25 JUST INCASE I COULDN'T 😝 informative video thanks boss

@bigzoffroad Жыл бұрын

It’s the little things i enjoy so much! Haha

@jacobhendleyguitar9838 Жыл бұрын

Woke my dang baby up with that!

@bigzoffroad Жыл бұрын

@@jacobhendleyguitar9838 🤣

@jodiegould7102 2 жыл бұрын

Another note about the smell of coolants. Dogs are attracted to coolant leaks, so make sure your dogs don't have access to any leak spots.

@elelectrotech9374 11 ай бұрын

the after market thermostats dont last more than a year,i just had one fail after 6 months get a mopar.

@bigzoffroad 11 ай бұрын

I’ll keep an eye on it. Normally components like this i stay with mopar, but the price difference was a but hard for me to ignore and i went with the cheaper one. I’m not a fam of the nylon thermostats at all. I’ve seen them fail multiple times and it’s not a great time

@jacksjeepinchannel5349 Жыл бұрын

I have the same issue with my 2014 Rubi. If I hold 3K foe long it'll start to overheat but with I letit shift gears it quickly cools back down. I'm sure I need to flush my system. Thanks for this video.

@hondaracing9199 Жыл бұрын

What ended up fixing your issue?

@jacksjeepinchannel5349 Жыл бұрын

@@hondaracing9199 Haven't fixed it yet. First thing I'm going to do is though is clean the radiator. Then go from there.

@jimmyjones6816 11 ай бұрын

Hey guys I’ve been dealing with an overheating issue on my 2012 Jk Rubicon. I replaced the thermostat twice with aftermarket units.because Mopar units have been on back order for a year and it would still run too hot climbing a hill or when accelerating. What I found is, the aftermarket units are not only junk but are assembled with the spring upside down! I noticed the new one in this video has the spring upside down also! Another thing with most aftermarket units is the struts the spring retainer is mounted on are too short! This reduces the amount the thermostat can open! I have however found an aftermarket on Amazon that is not junk, has the taller struts like the OEM, and is made with an aluminum housing! It’s sold under the name MILIPARTS. I hope this helps, By the way, this video shows a good way to flush the cooling system! Jimmy

@bigzoffroad 11 ай бұрын

Oh interesting! I’ll look into that! I have no way to see if my coolant is flowing as well as it should be, but since I’ve flushed the system and replaced the old thermostat i haven’t had an issue except when I’m really getting on it on a trail. And even then i can just let it sit for a minute or two and it catches o up

@bigzoffroad 11 ай бұрын

Also! An aluminum housing would be nice! I’m gonna look into that! Not a fan of the nylon everything on these engines

@FR4G0UTX 4 ай бұрын

You sir are the reason why I read the comments

@jessegatlin8832 3 ай бұрын

I know this is 7 months later, but how is your miliparts thermostat doing? Was that a permanent fix?

@jimmyjones6816 3 ай бұрын

@@jessegatlin8832 Yes Jesse, it's performing just like the original! After I installed it, the Mopar unit I had ordered finally came in but I have no need to install it at this time because the Miliparts unit is fine!

@djdarkopz1662 Ай бұрын

Already replaced thermostat 2X, vacuum lines with coolant flush, Burped, changed coolant sensor, and still overheats. Ordered a different thermostat so hopefully this is the charm. 2015 Rubi JKU with 86k

@bigzoffroad Ай бұрын

I would recommend only using the OEM (Mopar) thermostat. The aftermarket thermostats are rated differently. But also, have you done an exhaust gas check? Make sure it’s not a head gasket? Are you leaving coolant from anywhere? Is your radiator fan turning on? There’s some big relays for the radiator fan, are those fried? And, do you have grille inserts?

@djdarkopz1662 9 күн бұрын

So the solution was a new thermostat again, but this time I ordered a better one online, not Chinese made. OEM are backordered for months. It was a thermostat from Gates

@bigzoffroad 9 күн бұрын

@@djdarkopz1662 okay nice!! Glad that fixed it. A lot of OEM parts are just back ordered all over the place, not really sure why

@rdubbz 7 ай бұрын

I slightly seen your sticker on the back windshield is that Runescape related?

@laragreene8328 11 ай бұрын

I have the same problem......i'm now looking into the Coolant temperature sensor and Temperature sending unit. The last one mentioned is under $20. The other one is around $35.

@bigzoffroad 11 ай бұрын

Could those be tested with a multimeter? do a continuity check? That was my next plan of action, but my thermostat and horribly contaminated coolant seemed to be the culprit of my issue. Do you feel like your fan is delayed on kicking in? I feel like my Jeep's temperature kicks up higher than it should before the fan finally kicks on, and then has to work extra hard to catch up.

@laragreene8328 11 ай бұрын

@@bigzoffroad YES YOU CAN TEST THEM.....do a quick youtube search,there are videos showing how to!!! iF ANYTHING MY FAN RUNS TOO MUCH....lol.....it seems to always be running. I also have that whining sound occasionally!!! I have a new radiator and new thermostat. Its still running hot!!

@bigzoffroad 11 ай бұрын

@@laragreene8328 if you’re having the same whining sound that you can hear in my videos, that was just a trashed idler pulley. Super quick fix. I wasted a whole day trying to repack the bearing and stuff… no good, just replace it

@Steve-zq8ge 11 ай бұрын

Only worked temporarily. Problem back again. Replaced thermostat 4X, O2 sensor 3X, radiator cap, coolant flush 2X. Burped the system. Still get P0057 and engine overheats. Would love a final solution to this overheating problem.

@bigzoffroad 11 ай бұрын

Hmmm I can’t see why the P0057 code would be related to overheating. So you’ve replaced the Bank 2 O2 sensor (should be Driver side), but did you inspect the wiring harness and connectors to make sure there’s nothing broken, grounded, or corroded? Because that code is for low voltage signal from the O2 down stream sensor. As far as overheating, have you tested your radiator fan to ensure it’s actually firing up? And when does it overheat? All the time? Maybe do an exhaust gas check in your coolant for a possible head gasket leak?

@vman992mah2 5 ай бұрын

Having a similar problem. Waterpump. Thermostat. Temp sensor and radiater was diagnosed as the problem it was leaking on the core. Driving and coolant gauge goes to mid section and goes up a bit. Fans run full speed non stop until the car us switch of. Fluctuations on heat gauge. No fault code guys please assist. Tested for gas leaks in cylinder no issues there. Only thing not done is radiater fan. I m completely stucked guys please assist. I haven't checked it radiater fan as I saw it was running good on the car car while stationary. As soon as u drive maybe after 20min while driving gauge goes up and back to mid section. Please assist

@djdarkopz1662 Ай бұрын

@geneedwards7619 6 ай бұрын

Need to turn on your heater on full hot, fan speed is slow that lets the coolant fill up the heater core.

@bigzoffroad 6 ай бұрын

Yeah, when you’re burping the system? I did 👍 But now my radiator has a leak somewhere. Very very small. Still no overheating issues though.

@dirttales Жыл бұрын

I wouldn't use regular tap water to flush.. Fill the system with distilled water from the grocery store and drain it after driving around for a bit. The stuff that is in regular tap water will corrode your engine..

@bigzoffroad Жыл бұрын

Distilled water, or one of the coolant flush systems. I’ve not had an issue with using the hose before though. I flush my system about once a year.

@harrisonzogby8014 Жыл бұрын

I’ve had the thermostat, radiator, manifold gaskets replaced between august - November 2022. Then I just had the cooling fan replaced after it was running loud & hot a month ago. Now after being replaced it running hot & loud again but not as bad. I’m guessing I need to replace the water pump

@bigzoffroad Жыл бұрын

Have you done an exhaust gas check to make sure it isn’t your head gasket?

@harrisonzogby8014 Жыл бұрын

@@bigzoffroad That I have not done yet

@bigzoffroad Жыл бұрын

@@harrisonzogby8014 do you have the 3.8l V6 or 3.6l? It’s possible that you have a small leak in the head gasket somewhere, and testing the coolant for exhaust gases isn’t difficult, so I would test that just to be sure. Bleepin’ Jeep does a good video on how to test for exhaust gases.

@harrisonzogby8014 Жыл бұрын

@@bigzoffroad I have a 2017 with a 3.6 76k miles. I’m thinking that it might be a leak, but my mechanic thinks it might be the thermostat again

@matthewdylenbrown Жыл бұрын

how much coolant were you able to fill it back up with? manual says 10.5 quarts but i feel like I'm barely getting half of that in and out of it

@bigzoffroad Жыл бұрын

So, the engine block holds so much extra coolant. Draining it all out is quite the task, which is why i just flushed it out. I didn’t measure what poured out exactly, but I’d say maybe 2 gallons? I put in about 2 of those bottles back into it after all was said and done.

@bigzoffroad Жыл бұрын

When i flushed it out, quite a bit more coolant came out before the water started really running clear. Same with my radiator.

@baseball012001i1 Жыл бұрын

After you took off the thermostat housing leaving it open, did you attach it back on to start the engine block flushing?? Thanks

@bigzoffroad Жыл бұрын

You mean when i was pumping water through the block? Yes, you’ll have to pull the innards out of the thermostat housing and put it back on to get the hose attached back to the engine. With these when you buy a thermostat in comes with a new housing anyway, so just do that with your old thermostat. Sometimes when you pull apart the thermostat insides, that spring launches things everywhere. Mine was pretty worn out, so it was very easy.

@baseball012001i1 Жыл бұрын

@@bigzoffroad thanks for your prompt reply as I’m currently doing that same work on my 2010 jeep wrangler

@bigzoffroad Жыл бұрын

@@baseball012001i1 that’s the 3.8l, different engine. Not sure if their thermostat housing is setup the same, however, same rule applies with just about any thermostat. You can remove the insides.

@nonayerbidnet6974 10 ай бұрын

Like, thank you.

@bigzoffroad 10 ай бұрын

🤣 hope it helps!

@lbcoach2295 11 ай бұрын

My 2013 wrangler overheating today 79,000 miles. Replaced thermostat twice in 2 yrs. But never had overheating issues. Not only did it overheat but I had a huge antifreeze leak. Not sure what it is. Guess I'll find out when I get it to the shop tomorrow

@bigzoffroad 11 ай бұрын

Hmmm Could be a blown radiator, hose or even a blown head gasket (i hope it’s not that) Best of luck to you!!

@bigzoffroad 11 ай бұрын

Let me know what you find out!

@lbcoach2295 11 ай бұрын

@@bigzoffroad I'm not sure it's a head gasket because I wasn't losing any power driving. That happened to me in another car and I couldn't go more than 50 or 45. There was antifreeze everywhere last night. All on the right side. I'm waiting for the tow truck now

@lbcoach2295 11 ай бұрын

@@bigzoffroad ended up being a bad hose clamp. I paid more to get it towed

@bigzoffroad 11 ай бұрын

@@lbcoach2295 well! Easy fix, glad that worked out

@kurtnulf3362 Жыл бұрын

If you still overheating after this it might be that the fan motor is bad or the rheostat that turns fan on is bad

@bigzoffroad Жыл бұрын

So, I’m not overheating anymore, except when i am doing long hills on the highway (like going up and over mountain passes), but when it does that, it heats up a bit then catches up with itself. So i have been thinking, and that rheostat is exactly what I’m thinking of! It just seems like it’s delayed, like it waits to long to turn the fan on. The fan itself, I’ve checked and ran it at all its different speeds manually, and it’s fine, it’s Motor sounds good

@paulbrowning1758 Жыл бұрын

Don't you also need to flush the heater core separately? If not, you'll still have old fluent in the system.

@bigzoffroad Жыл бұрын

Should! I didn’t this time. But the same method applies. Pop the heater core hose off at the water pump and the return, and stick the water hose in there and flush it out until it runs clean.

@bigzoffroad Жыл бұрын

Ultimately what i was trying to accomplish was clearing out any obstructions from my fluid being so contaminated. Yeah, not clearing the heater core will just contaminate again, but that’s not an issue I’m to concerned with right now. I’m pretty sure my water pump is coming to the end of its service, so I’ll be flushing the whole system again when i change that out, and I’ll run a coolant flush through it to help really clean out any contamination.

@sandcrewus1362 Жыл бұрын

Look at be spring, on one thermostat vs the other.

@frankbaublit Жыл бұрын

i was wondering if you could let me know the screw driver information

@bigzoffroad 9 ай бұрын

You loosen that top screw a bit, run the engine and let it warm up. Coolant will start to “bubble” out from under the screw. Once it’s not bubbling out anymore (as it it’s just straight coolant flowing out, no air bubbles) close it. System is bled. 👍

@rudywahlers1085 2 жыл бұрын

So did it fix the problem or did you change the water pump?

@bigzoffroad 2 жыл бұрын

So far, no issues! Still have that nasty idler pulley sound. Planning to address that in another video :)

@lgroves336 Жыл бұрын

@@bigzoffroad I have seen numerous videos about Jeeps like your overheating because of air in the system. Seems the air alone causes the engine to run at least 20 degrees hotter.

@bigzoffroad Жыл бұрын

@@lgroves336 i think the same thing. It seems to me like it creates air pockets at Junction points (ei. Thermostat, water pump) and because it pressurizes differently than the fluid, the fluid has to build up more heat before it can force through the air pocket. Because, the temperature rises, but it isn’t runaway. It just heats up more than it should. And if you listen, it sounds like coolant isn’t flowing through until it heats up an additional 10-30°. Some people have drilled holes in the center of their thermostat so it passively allows fluid to move through even when its “closed”. This seems to fix the problem for a lot of people, and it’ll be the next step for me if the issue comes back again.

@bigzoffroad Жыл бұрын

@@lgroves336 fact of the matter is, if you’re offroading, there’s situations where you will be putting your engine under a lot of pressure and strain. It’s gonna heat up and that’s fine. But small amounts of air in your cooling system shouldnt have such a drastic effect on it’s performance.

@TheTaytoni Жыл бұрын

@@bigzoffroad im having the same issues you are with over heating temp my ranges from 222-240F specially going up hills. my pulley sound started after i hit several mud puddles lmao.

@ddunerider Жыл бұрын

Did it work ?

@bigzoffroad Жыл бұрын

Haven’t had overheating issues since!

@leskobrandon538 Жыл бұрын

I see mud in the radiator fins... That would make it run hot...

@bigzoffroad Жыл бұрын

Yes there was, and has been cleaned out, i didnt have it in the video. Cleaned my whole engine bay out including trans cooler and radiator.

@6738 Жыл бұрын

Flushed my jeep today with this method. After when i got everything back together went to fill it but it only took 6L (needs 10). So I used the same funnel as you, let the car idle and waited for the thermostat to open and pull the rest in. Instead i noticed the funnel start filling up almost overflowing. Also heater blows cold. Tried squeezing the hoses to burp some air and it did do some but again when i let it idle with the funnel in the cap it starts to overflow instead of sucking in. Any ideas?

@bigzoffroad Жыл бұрын

My best guess here, your thermostat isn’t opening, not allowing fluid to flow through, but as the engine heats the coolant, it expands, as well as gets pumped through the radiator. As for heater blowing cold, that means there’s air somewhere in that system, and the coolant isn’t getting to the heater core. Make sure when burping that your heat is on so it flows through everything and flushes those line out, also, parking at a slight incline (front end up) can help air travel to the radiator. If you’re on a JK, the thermostat does have a small bleeder valve on top of it as well. In my video I didn’t use it, but i have in the past on mine and others. Did you replace your thermostat when you flushed the system?

@6738 Жыл бұрын

@@bigzoffroad yea changed the thermostat out. Also been running the heater fan on low. Engine gets up to "operating temp" on the gauge but heater still cold. Also upper rad hose stays cold as well

@bigzoffroad Жыл бұрын

@@6738 right, and that’s your return hose, so that really indicates that your thermostat isn’t opening. It might just not have built up enough pressure to pop open yet. They’re usually rated for about 190 - 210° which is when they’re supposed up pop open. For the heater, only reason i can think of it still wouldn’t be blowing hot air is because there’s air stuck in the system there.

@6738 Жыл бұрын

@@bigzoffroad hey so this morning (-4⁰c canada) tried adding some more coolant. The jeep took some in the rad managed to get a little more air out. Started the engine with the funnel barely full. Got up to temp and then started overflowing again with no heat out the heater core. So i let it cool and put the rad cap back on and started it again. Let it get to temp, climbed slightly above half then all of a sudden i can hear the coolant swish around in the dash moving thru the heater core. Finally heat! Now im just gonna let it cool down and try to add more coolant

@bigzoffroad Жыл бұрын

@@6738 That's good!! Yeah so I wonder if it just wasn't building up the needed pressure to push through an air pocket. Heat soak can be a touchy thing. If I'm only trying to get a little air out, I put very little coolant in the funnel, that way there's room for expansion while it's waiting to pop open the thermostat, btw! Glad it's working for you now! That Canada cold, you need your heat!

@Hb-fr3sk Жыл бұрын

I’ve got the same issue and replaced my water pump and not yet fixed, can’t drive RPM more than 2,000 Please if you knew how to fixed help me

@bigzoffroad Жыл бұрын

That’s more extreme than my issue. You may have a blown head gasket. Have you done a block check to see if there’s exhaust gasses in your coolant? kzfaq.info/get/bejne/gbKSqJp5rtaYl6c.html

@bigzoffroad Жыл бұрын

Also, have you tried driving around with your thermostat opened? In my video, how i left all the insides of the thermostat out. If you drive around like that, and you DON’T overheat, then you know the issue was your thermostat. It’s Something else to try. There’s a lot of variables within the cooling system. But there’s simple ways to test most of it.

@Easymac2007 Жыл бұрын

My fkin ears! and i'm on a laptop 🤣

@bigzoffroad Жыл бұрын

But that suction noise hits the spot! I edited out most of me messing with that hose… hahaha

@cmkpro81 4 ай бұрын

You didn’t flush your heater core..

@bigzoffroad 4 ай бұрын

I didn’t

@cmkpro81 4 ай бұрын

@@bigzoffroad I’m having the same issues. Only my radiator fan won’t turn off. I replaced everything….. sensors, thermostat, fluids…. My pump is fine. I believe it to be the thermostat though, it’s not Mopar. I was told that Jeeps are very particular about the OEM thermostat. So I got one that will be here Monday and I’ll see if that fixes it.

@bigzoffroad 4 ай бұрын

@@cmkpro81 i don’t think the thermostat has any control over the fan turning on or off. That’s all controlled by the relays being fed information from the coolant temperature. But yeah, i would only use the MOPAR thermostat. Also, you could take your current thermostat and gut it so it’s just wide open (remove the spring and seal) and see if that works, because it could be that your thermostat isn’t opening? So as soon as you turn on your jeep, the fan is just running? Or once it starts it won’t stop?

@cmkpro81 4 ай бұрын

@@bigzoffroad it turns on when I get up in temp and stays on even when it’s cold outside. It goes up and down. I stop at a red light the fan slows cause temp goes down. I speed up fan goes up.

@bigzoffroad 4 ай бұрын

@@cmkpro81 is your engine overheating or maintaining temp?