Karen Thomas

Hello everyone, I am new to this forum and new to caring for my Jeep on my own. I have been having problems with it overheating for some years. It has had work done on it to try to stop this from happening - replaced the overflow container, drained and replaced the fluid, replaced the radiator (about three years ago), and finally replaced the thermostat which was "gummed" and that fixed the problem for about six months, but today it overheated on a trip less than a mile from my home - meaning it was smoking, smelling of anti-freeze, the overflow was halfway with fluid and bubbling (it has some soft brown unidentifiable things that float to the surface when I add fluid to the overflow), the radiator cap was too hot to touch (when it cooled it was full and the fluid was green), there was a hissing noise from somewhere towards the back of the engine that I could not define or locate, and the guage inside the car was nearly two lines past the halfway mark (normally it is halfway). I realize this is like leading the blind since I know nothing about the workings under the hood, but I could really use some help. Anything would be appreciated. Thank you

EZEARL

HEY Karen. Welcome to CF.
Your Cherokee has an 0331 cylinder head that can be a problem. Here is a link to help you to diagnose your issues.
https://www.cherokeeforum.com/f2/00-...erview-118922/

Karen Thomas

Thank you, Earl. I don't have any of the symptoms listed for the cracked cylinder head. As a matter of fact, I ran the heat on high in hopes that would help a bit. Before the thermostat was replaced and the engine overheated, running the heat would significantly drop the engine temp. It worked this time, just not as quickly. Also, I do not lose anti-freeze since the overflow chamber was replaced. It is almost like there is a blockage somewhere.

drewactual

these things eat caps... pick up a stant 16# cap and slap it on... wait for the engine to be cool first, though...

that said- if you're overheating, whether the head casing was cracked before is now moot- it almost certainly is now.

Karen Thomas

The hose i am touching (along with the one running directly parallel under it) got very hot very quickly. The large hose to the left stayed cool until I shut the enging off after about 10 minutes of running. The hose that runs from near the radiator cap to the overflow stayed cool. The overflow container drained completely when I started the car (I guess that's supposed to happen?) BTW the temp guage stayed below half. The fan ran fine, and no smoke this time. (I believe it was a branch caught under the engine from fooling around the other day).

Karen Thomas

If these hoses are supposed to get that hot, then I will get a new cap. Thanks, Drew

BlueRidgeMark

Erm, ah, yes you do, possibly. Right here:



There is a kit you can get from most auto parts stores that tests for combustion gasses in the coolant. I suggest you start by getting one and following the directions. You need to know.

That said, it's also possible that some previous owner put some stop leak in there which has gunked up your system. There is one famous one that is brown, and would look like what you describe.

If that is the problem, a flush is needed. See my sig, #4.

Karen Thomas

Thank you for the post Mark, but that has been happening for the last 4 years on and off. I've owned this jeep for 10 years. Other than occasionally overheating, she drives like a champ. Has a steady idle, excellent take off, and an all around great ride. I love this Jeep. She's my go-to favorite even with my new Patriot. After different things were fixed, and yes, someone put stop leak in there on one or two occasions, (and if I remember correctly when he poured it, it was brown), it would stop for a while. The best she ever ran was after the thermostat was replaced six months ago. I don't know what happened today, but after removing the cap from the radiator, checking to see that it was alright, and replacing it again, I started the jeep back up, ran the heat, ran the a/c, noticed that the overflow tank was now empty (it was too full before I started messing around today), filled it to the cool line and let the jeep idle for 20 minutes or so, (a very pleasing idle) the temp. guage was steadily below the midline. So I took it for a spin, and it didn't reach the midline at all and the overflow tank was still at the cool level. I don't know what is going on, but I will do the Amway Flush to start with. Thank you for your advice

NewbJeep

Unexplained coolant loss is a symptom of a failed head gasket or cracked head. The 0331 head cracking isn't an "if" it's a "when." If you love your XJ and plan to keep it, replace the head.

BlueRidgeMark

There! I fixed it for ya!

Karen Thomas

Well, today was the first time in six months I've had to add a half a quart of 50/50 to the overflow tank. Hopefully, I've got more time with her, cause I sure don't have the money.

NewbJeep

Thanks!

extrashaky

Unfortunately it really does sound like the 0331 head crack. That wouldn't mean the Jeep has to go away. If you catch it in time, replacing the head takes a few hours and can save the bearings in the engine. On the other hand, if you have a cracked head and don't take care of it, you will lose the engine. So you need to know for certain whether it's cracked, and you need to find out sooner rather than later. Don't wait around hoping it's not.

The combustion leak test discussed above is a good start. The boiling coolant in your overflow bottle is a likely sign of exhaust gases leaking through a crack in the head or a failure in the head gasket. Brown garbage in your cooling system is also a potential sign of exhaust leaking, because the hot exhaust gas boils the water out of the coolant, leaving behind that brown sludge.

Another symptom of a crack is coolant getting into your oil. You can't always tell this is happening by looking at the oil. The only way to rule it out is to send off an oil sample to a lab like Blackstone. They'll send you a free sampling kit, and the test itself costs $28.

Sometimes you can actually see the crack with your naked eye. These heads usually crack right between the #3 and #4 cylinders, right under the oil filler cap. If you take the cap off and look down in there with a flash light, you may be able to see it. Note that this is just a way to rule the crack in, not out. If you don't see a crack, it doesn't mean you don't have one.

You can also do a compression test on the cylinders. If the cylinders will not hold compression, that's another sign you have a crack, a leaking gasket or a valve problem.

If you have exhaust in your coolant, coolant in your oil or a loss of compression, the head has to come off. A redesigned 0331 with a thicker deck that doesn't crack will cost $500 or so. Clearwater Cylinder Head in Florida is the most popular replacement, and that head comes ready to bolt on.

As for labor, I don't want to make any assumptions: Can you do the work yourself? If you have to pay someone else to do it, it will probably cost another $500 to $700 unless you can find someone willing to give you a break.

So while I know you said you don't really have the money to deal with this right now, given your symptoms I don't see how you can afford not to confirm whether you have a head issue. And if you do have an issue, is it worth the cost of parts and labor to keep your Jeep on the road? If you can't afford to fix the Jeep, can you afford a different car a few months down the road when that motor gives up?

freegdr

What colors oil on dip stick if your loosing coolant into oil it will be grayish on dip stick. Cooling system needs to be pressure checked including the cap itself.

Karen Thomas

Good Morning, freegdr, the oil dipstick has always showed a perfect oil color or if I am in need of an oil change, it is a brown, dirty oil color. It has never been gray. I will be doing a combustion leak test today.