Strange Over-Heating. Bottle Fills Up in Five Minutes!

Strange Over-Heating. Bottle Fills Up in Five Minutes!

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‘89 Cherokee I6 Auto - Closed Cooling System

All hoses, water pump and thermostat one year old. Cooling system was back flushed and purged and installed fresh Anti-Freeze one year ago.

Radiator about five years old.

I just developed an over heating problem and it seems strange. This has been happening in about 45F Degree temps here in New Jersey, USA.

With the engine cool I drive for five minutes, stop and check under the hood...what I find is the bottle is filled to the top with anti-freeze and it’s trying to come out the cap. I can touch the bottle and it’s a touch warm but almost cool.

I’m unclear what’s happening as the engine/anti-freeze isn’t even up to temp yet and it’s trying to shoot out anti-freeze.

Thermostat? Water pump? Blown Head Gasket?

Many thanks!

Sounds like the cap on the bottle is bad and it isn't holding pressure.

Hmm...I hope it's that easy. I'll see the dealer on Monday and pick one up...

But the first time it ran hot it did not leak and the bottle was filled up. The gauge was over 210 but the bottle wasn't too hot. It started to leak anti-freeze after I loosened the cap as I thought the bottle was going to explode.

I'll give a new cap a try.

I had this problem on my Trans AM.

it was the radiator cap..i think it had a release valve that wasn't working.

I second the cap problem. Went through a couple of them before swapping the cooling system to the newer style. No guarantees, but it's a cheap, easy thing to buy that rules out one problem, if nothing else.

Enjoy the Jersey shore. I have a friend with a home on LBI...I don't get back to the shore often enough. Happy Holidays.

-Rich

Either put a new plastic turtle on or cruise the boneyard for a ford, they have closed systems, even the new ones only the bottle is brass/steel with a normal cap on it. Then it's just a matter of fitting it to the shelf. Also if it did overheat the tstat is probably toast. Quadratec sells them alot cheaper than the dealer does and their shipping is usually one to two days normal shipping. I just bought two tuffy stereo center consoles for the kids wranglers, ordered on monday got them on wed nite..

rich,
Any particular models that have tanks well suited to the XJ/MJ? I'm very intrigued, my bottle is starting to look a bit worse for wear. I think it may burst soon, I would like to replace it with a metal tank for sure.

If you're looking for a pressure bottle swap, any year up to (and including) '90 will work. Last summer I swapped out the whole system with new parts for a '92 so I did away with the pressure bottle altogether. It's a popular (if not controversial) swap that fit into my budget nicely...at the time I needed to replace the radiator anyways. Hope this helps.

Oh, before I did the swap, I Herculined the outside of my pressure bottle so it would still flex under pressure, but be more resistant to cracks. It worked fine, but I'm not sure if it would have worked fine without the treatment, too. It seemed like a good idea at the time and a buddy had a little bit of the stuff leftover. Not sure of anyone that makes an easily-fittable metal tank for the pressure bottle without hitting Jeg's or Summit or the like.

-Rich

Just in passing, the newer mustangs have metal tanks, the only reason I know this is one of my customers/friends has a 8 bay shop and I work on his snapon computer systems and spend time wandering round between reboots. Until then I had thought the closed systems were long gone but they made a comeback, gives the auto designers more options when they don't have to deal with filler necks and stuff on normal raditator for nose and hood design I guess. VW's have them too but the tanks are plasic with a really weird cap. I don't have any closed systems so I never persued it any futher other than warren saying that he sees alot of new cars with closed systems and most use metal tanks, flat, about the size of a cigar box and they even have an overlfow tube like open systems to you can also put in an overflow tank if you can find room. Eagle also has a solution, metal expansion tanks, thats what they are officially called, all the radiator manufactures have them in varying sizes, eagles is one from summit racing and is tublar aluminum.

The only thing I like about the plastic surge tank is the ability to visually check the coolant level without removing the cap. But it seeps off & on out the cap and is just ugly to look at when it gets that buildup of scackum inside & out that is the first thing I see when I open the hood. When it comes time to change it I'll probably adapt a metal one just because the plasic one is so unsightly.

We sell Sterling (used to be Ford) trucks at our shop and they use plastic surge tanks and we sell a lot of replacement tanks because they are splitting open all the time. They are worse than the Jeep ones because they are flat rectangular tanks. A cylindrical shaped tank like the Jeeps use is much better at staying together under pressure.

Just to give an update...

The cap on the bottle was replaced and my overheating/boiling-over problems are gone!

Som-Oh-Bitch!...I wish all fixes were this easy.

Many, Many Thanks guys I would have replaced everything but the cap to fix the overheating/boiling-over problem.

The cap I replaced was about eight-years-old and I noticed the new cap is a little different design...it's taller, built more substantial and the inner stopper is much longer. Don’t know when Jeep updated the design. If it lasts another eight years I’ll be happy!

As much as I would like to replace the plastic bottle with a metal one, I do like the easy visual level check. The closed system has been really trouble free for the past 11 years so no reason to switch to the open system.

Once again thanks for all your help!

Happy Holidays!

John V

With some originality and a bit of work you could put a sight glass in one of the metal surge tanks, two 90* elbows, piece of glass tube rated to 100PSI, drill two holes and thread the 90's in. Any good boiler shop will have the parts.