My 1999 jeep Cherokee overheats. I'm getting up to 225 before I have to shut off the engine, it only gets that high when crawling on a trail, when I'm on the highway its 210 and idling it is about 215.I have a new water pump and serpentine belt. I have a new fan clutch, I have a new fan shroud on it, a new 195 T stat, new hoses, no cracks in radiator, I also flushed the radiator to see if that helped no dice. i don't know if this has anything to Do with it but my heat is not very hot it's just warm. I've read this can be because a bad water pump? but mine is only a month old..... I have not yet reverse flushed the heater core either though and I've heard this could fix the heat..... So any suggestions on how to keep my engine from overheating? I've heard electric fan mod but it just seems to advanced for me what are some cheap things I can do ? or what is causing this so I can fix it!!!!!!

 

How's that block of yours? Cracked?

 

Uh...
What?

 

Currently the block is not cracked... it was replaced a month ago from cracking, so I'm trying to figure out how to stop it from overheating before I crack it yet again!

 

Here's a tip for you:

Thanks for your post. Please understand that we’re here to help and we enjoy our Jeeps as much as anyone else.

That said, also be aware that we need good solid info on your Jeep so we can provide the most accurate info to you without wasting any more of your time or money in getting to the root of your Jeep’s problem.

Also, please be aware that during an open thread/survey here on Cherokee Forum it was found many members, both new and seasoned, will skip over posts that prove difficult to read. Those kinds of posts include run-on sentences and little or no punctuation.

Please keep these things in mind as you post so that you can reap the most benefit from this forum.

 

Thanks for the advice! Does anyone know how to fix this overheating issue???

 

Have you changed the radiator?

I never had a problem with the cooling system on my '97 (5.5" lift, 33's etc. no where near stock and in Hot SoCal) until my OE radiator finally cracked a tank a few years ago. I swapped in a $99 O'Reilly "OE" radiator thinking I'd be good because the stock one had worked so well for so long, and soon as hot weather rolled around I started having nothing but problems with high running temps and over heating. Changed thermostats, water pumps, fan clutches, flushed, flushed again... chased it for quite awhile and finally after researching every thread I could find on the internet came back to the new O'Reilly "OE" radiator. So I bought and installed an actual OE MOPAR HD (heavy duty/towing package) radiator and haven't had an over heating/engine temp problem since. MOPAR part #52080104AC.

FWIW: The O'Reilly unit might work just fine on a bone stock XJ which is what it was no doubt designed for.

Good luck.

 

Put in a fresh stock radiator. Cheap DIY project and easy enough to do. Probably cost you 100 bucks total, less if you shop. You could always break the bank and get a flexalite. 900 bucks and gets rid of the fan clutch as well.

 

You might want to try a mechanical gage. Installed one on my 96 XJ a while back and found out that actual coolant temp was about 30 degrees lower than what the dash gage was showing.

 

Wow this rudeness makes me not care about your over heating issue. And i know for a fact mr and cruiser and the seasoned members have the answer.

 

Ummmm sycoglith no ones being rude here expect maybe the comment you made.... I was genuinely saying thank you for the advice, and I acctually edited all my posts and added proper punctuation. Im new here and I don't know you or really anyone on this forum..... but I would truly hope people could tell when someone is genuinely thanking someone as I was. And again guys thanks for the advice I have the stock radiator I have changed it but I went with the stock one for a 1999 Cherokee. Is it just not good enough for my lift and tires??? Or could it be something else?

 

I would verify that your gauge is reading right. A mechanical gauge would tell you a lot.

I have heard of people getting water pumps that have the fins set-up for rotating the wrong way. I don't think your 99 makes the list for vehicles that this could happen to, but it's worth looking at.
Have you tested your t stat? Throw it in some water on the stove with a food thermometer. It should start opening right at 190ish.
Go basic and hit the obvious first.
Have you bled the air and are positive that you don't have some in your system?

You'll find it....

 

I didn't catch if you mentioned anything regarding your electric cooling fan. If it's not operating when required you will get a temperature spike. It could be a number of issues from the 40 amp fuse, the relay or even the fan itself. I just had to change out my fan. It was faulty and drawing excessive amps to the point that the fuse would fail. While you're in there, back flush the heater core. Amazon had the best deal on an aftermarket fan. 55 bucks shipped.

 

You sound like you've really done a lot. You mentioned replacing a cracked block and going through the cooling system except the radiator which it sounds like you have now done. There is a high flow water pump but it's only a minimal change. So going through the cooling system on the Cherokee in the order of common failure kind of looks like this:

Fan Clutch- be aware there are occasional failures on a new clutch due to poor quality imports. So don't assume it's good because it's new.

Temp sending unit-clean the connection and put in a new one.

Thermostat- same issue as above, buy a good one.

Water pump- you can do a high flow for more money but it only claims a 30 percent flow increase. Not usually worth it.

Radiator- factory is usually a two core aluminum with plastic catch tanks. There are some single cores out there so avoid them. The two core was the option on the tow package. Make sure you are using the right coolant mix for your vehicle.
Three cores only work if you install a really strong electric fan.balso make sure you installed a new cap, don't use the old one.

Belt slippage- check the tension on your belt. If it's loose it will not turn the mechanical fan properly and could contribute. You can get a belt checker for like 15 bucks.

Heater core- it's part of the system and needs to work. Swap the core or back flush it. On a properly working core, you can switch to heat on a hot day and watch as the temp drops. It's like a little back up radiator.

If you've done all that and still overheat off road then it's time to get funky.

Remove any under hood insulation.

Consider hood louvers. Several vendors, all look cool on a lifted jeep.

I use rockstar hood blocks. Raises the hood about an inch at the back, looks good. Can't say if they work yet because it isn't hot.


I have done everything you did and had the same result till I did the radiator. After that it was all good.


Hope this helps and keep asking questions if it doesn't.

 

I do have a squealing noise really loud whenever I turn the ac on sounds like a belt. but if I turn it back off and on a few times it eventually starts running without the squealing noise, never thought it could contribute to my overheating issue??? is this a possibility? I will boil my t stat when I get home, and back flush the radiator. which way is the clutch fan suppose to spin? Just wanna double check it's going the right way. Does anybody have a suggestion on some good priced good vents?