Hi everyone,

Here is what happened:

About an hour ago I was drove back home from walmart in my 1989 jeep cherokee and everything seemed normal. Well, I pulled into my driveway put the jeep in park and was rolling up my windows (Jeep was still idleing) when I heared a sound like this: TSSSSS!!!! So, I looked down at my gauges and saw that my temp gauge was rising (It was at normal temp.). I turned off my jeep as quickly as I could before it got to hot and when I got out I saw my coolant leaking like crazzzzy from under my car.

When I opened the hood as saw that my coolant tank looked like it was going to Blow Up because it looked like a balloon and was shooting coolant out of a hole in the side of it.


Anyone have any idea why this happened? It is about 93 degrees outside but I only drove like 2.5 miles??? And it was not over heated till I heared it burst???

Thanks,
Daniel

Your cooling system normaly builds some pressure, about 15 psi.
Your radiator cap should release any excess pressure above 15 psi. So, if your cap is working properly, the coolant tank may just be fatigued and old and busrst under normal pressure. Get a new tank.
However, if your rad cap is defective it may have over-pressurized your system and burst your tank, so get a new cap, too.

Thanks for the information. I guess I will go get a new tank and radiator cap. Hopefully it want cost too much being as I recently had to spend about $1000 to fix its Death Wobble....

Thanks Again,
Daniel

I think you have closed system, there is no rad cap.

ok? So does that mean if my cooling system builds more then 15 psi it can not release pressure? Resulting in another busted coolant tank?

Daniel

ok? So does that mean if my cooling system builds more then 15 psi it can not release pressure? Resulting in another busted coolant tank?

Daniel

No. It means that instead of a radiator cap, the cap on the plastic tank is pressure rated and should also be replaced to be sure it is releasing pressure whenit should.

with it getting that hot that quickly, you may have a small leak that allowed air to get into the block. Once you replace the bottle and cap, check really good for other leaks.

Dude,

It appears that you are having mulitple issues. If your tank blew up the engine got real hot. The first thing I would check is the thermostat and water pump to insure that you have some kind of circulation. You will have to replace the tank if it blew up or atleast the cap. I would then 'burp' the engine. Venting the air out of the
block by loosening the temp probe in the back of the engine (while its not too hot). And checking the clutch fan for proper operation.


I went as far as just changing out my old radiator with a 1992 (three pass) radiator. The 1992 offers a radiator cap that you can see the circulation in the engine block. If you make this change you will need to replace the water resouvure and make changes to the heater valve (easy change). The change will be well worth it.

There are alot of past postings on our era Jeeps about "overheating"

Do some research and learn from others mistakes.

Hope you find it and keep it cool.

Dang that sucks... I really hope it isn't anything too bad because I just don't have any money right now and I need my jeep. I will search through some of the older posts on overheating.

Thanks for all the info.

Daniel

I think you have closed system, there is no rad cap.


89ltd, I was just reading in my Owners Manual on how to replace the coolant and it said:

"Filling Cooling System

1. Engine must be off and cool.
2. Remove radiator and coolant bottle caps."

and so on...

So that sounds to me like I do have a radiator cap... So should I get a new radiator cap too?

Thanks,
Daniel

89ltd, I was just reading in my Owners Manual on how to replace the coolant and it said:

"Filling Cooling System

1. Engine must be off and cool.
2. Remove radiator and coolant bottle caps."

and so on...

So that sounds to me like I do have a radiator cap... So should I get a new radiator cap too?

Thanks,
Daniel

And does it show where this radiator cap is?

hahaha!!! Yes, I guess that is the trick. I can't find a radiator cap anywhere. Nevermind.

There is a cap. It is on the passenger side tank, but burried under the upper core support.

Well, I replaced the coolant tank, cap, and just filled it with coolant/water. I was just wanting to know the best way to bleed any possible air out of the system? I can do it be unscrewing the coolant temp sensor, Right? I will do it in the morning and then take it on a test drive. I am hoping it doesn't over heat...

I let it idle for about 12 minutes in the driveway, right after I replaced the coolant, and the temp rose to just about 210 (I played with the gas, reving it up). Isn't 210 a little hot??? What do you guys think?

Daniel

Dang! Why doesn't anything ever go smoothly. This morning when I went outside to try to bleed any possible air out of my cooling system I ran into a problem.... When I went to pull the hood release handle it came all the way out (Broken hood release cable!). There was like 1/2 inch of the broken cable on the end of the handle.

It took me a while to figure out how to open the hood which I was able to do with a cloth hanger. Anyway, I was kind of pissed about my hood release cable being broken so, I just topped of the coolant and let it idle for about 30 to 35 minutes. It ended up maxing at about 210. Not to bad, huh? Does any one know any simple ways to get air out of the cooling sytem, that i can try?

Well, I guess I now need to start a new thread so I can figure out how to replace my hood release cable.

Daniel

If I'm reading right, your fill point is on the passenger side and NOT the radiator, and there's no radiator cap?

The fill point should be at the highest point, and bubbles should go there by themselves. Sounds like you've already done what needs to be done - letting it idle for awhile with the cap open. I'd just put the cap on, and drive, but keep an eye on the temp gauge for a couple of days.

One thing you might want to do is let it idle, cap off, and run the heater on full hot, just in case the heater core has some bubbles.

Thanks! Yeah, I have done all that including letting it idle with the heat on. When I took it out earlier the temp was good. At speeds between 50 and 70 mph the temp stays just a little over the half way mark between the 100 and 210 marks. When I stop and idle for awhile the temp goes up to about 210 though.

The only thing I really don't like it the new cap. It is like you can't screw it on really tight and once you get to a point it wants to pop back off. It is weird because the cap isn't threaded all the way around just on like 4 sides. Does that make sense?

Is there a way I can test my old cap to see if it works? This way I can keep it for an extra...

Thanks for the help,
Daniel

As long as your radiator cap is secure and not loose (in orther words, can hold pressure) it should be ok. Some radiator shops will test your cap to see if it's good.

I'm also thinking that beside the other problems, your radiator may have a restriction to flow. You wouldn't notice it in the winter (or highway speeds) but it could cause the problems you're having. It would be worth it to check, by popping off the upper radiator hose (with a cool engine) and looking inside the radiator. If you see some corrosion or buildup, think seriously about replacing the radiator.

Your Jeep is 16 years old, it will need a little more TLC than something new...

Well, it doesn't look like my problem was as simple as I was hoping... Today I was driving my jeep around and everything seemed pretty good. The temp would stay at about 185 when driving and about 210 at stop lights. Anyway, when I got home I was sittting in my driveway and thought I would just let it idle for awhile to see if it would overheat. So, I got out and did some stuff while it was still Idling. Every time I checked it the temp was holding at 210. So, after about 15 minutes I figured everything was ok and I wouldn't have to worry about it overheating if I got stopped in bad traffic.

At this point, I reached in through the window and turned it off. As soon as the engine had cut off it happened. All the coolant came pouring out from under my jeep and I could hear a "TSSSSS!" sound coming from under my hood. It took me a few seconds to get my hood opened (my hood release cable is broken), but when I did I saw that my coolant was spewing out from around my coolant tank cap.

My question is: Why would the happen? The temp was 210 when I turned the jeep off and it didn't happen till I had turned it off.

Why???

Thanks,
Daniel

While it's circulating, the coolant doesn't get above a certain temperature (say 210*). Once you turn the engine off, the coolant that is in the engine block gets hotter and hotter (since the engine is still hot, but fluid's not circulating) and tries to expand. It sounds like your radiator cap isn't sealing properly, I'd start with that. What happens is that as the temperature climbs it puts pressure on the cap. The higher pressure maintained inside the system is what keeps it from boiling. Once it gets past your (defective) cap however, it hits the lower air pressure and starts to boil -- the very good reason never to open your cap when the engine is hot.

One other thing that bugs me, is the 30* difference between when the vehicle is moving and not moving. I'd still take a look see inside the radiator to verify that there's a buildup in there. Just take off the upper hose when it's cool, and check inside with a flashlight. I'm sure you'll see some buildup inside.

Once you've replaced your radiator cap and radiator, you should be good to go for quite awhile.

You are not having the best of luck with your Jeep....

It is going to take some doing to replace that one...


I hope that others have good advice on that one..

I had my old coolant tank cap tested (It is good) so I put it back on and so far it hasn't boiled over again. I drove it 30 miles today (interstate) and the temp stayed just over the mark between 100 and 210. The temp. still wants to rise when I am stopped though.

I guess all I can do is get a new radiator...

Daniel

I think you should jump the electric fan where it plugs into the thermal switch so the electric fan stays on as soon as you start your jeep. I have mine that way and it helps a lot, in the fall I'll just removed my jumper connection. Normally, I think the electric fan comes on when its to late, wish I could thermal switch that would turn it on a little sooner than the factory one.

I think you should jump the electric fan where it plugs into the thermal switch so the electric fan stays on as soon as you start your jeep. I have mine that way and it helps a lot, in the fall I'll just removed my jumper connection. Normally, I think the electric fan comes on when its to late, wish I could thermal switch that would turn it on a little sooner than the factory one.

While a piece of wire is less expensive in the short run than a new radiator, you're asking for trouble with this band-aid. :nono:

humm? I might do that for now, but once I get some money I will put in a new radiator. I just don't have any money right now.

Thanks,
Daniel

I think the clutch fans on these rigs are non thermal, I put a new one on and didn't make any difference. At idle they move very little air, thats why as soon as you rev it a bit, even sitting still it will lower the temp. I have a new rad in mine but it was the thermastat that was the problem. It was put in backwards by the asshole who owned it before me. The spring was pointed into the stat housing instead of the block, in fact there wasn't enough room for it so it was crushed when he tightened the bolts. Most people I think would agree, with the older cherokees, if your in stop and go traffic or waiting for a train and temp starts to rise, if you turn on the a/c it will cool down right away because the electric fan comes on with the a/c.

Interesting... I have been running with the heat on. But should I slide it to AC when I stop at stop lights?

Daniel

there is a temp sensor in the rad on the drivers side with two wires coming out of it. Follow the wires to the connector, unplug the sensor and using a paper clip or a "piece of wire" , jump the two wires together, not at the sensor but at the wiring harness side. In this mode, the electric fan will turn on when you start the engine and come off when you turn it off. Just leave the jumper on for the summer, it doesn't hurt the fan to stay on all the time,it is designed to do just that. You should notice that it runs cooler, mainly when you are idling at a stop sign. This should help you out until you have the cash to fix the rad or what ever else is faulty.