• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Open Colling system ???

kenny811

NAXJA Forum User
Location
Damascus, OR
I have a 89 XJ, closed cooling (yeah it blows) If I cut in an after market filler into the top hose does this make it an open system?

Thanks
Kenny
 
I don't have any cooling issues out of my '87 with the closed sytem since I have replaced the t-stat, water pump, hoses, radiator, and flushed it. It works as it should.
 
kenny811 said:
I have a 89 XJ, closed cooling (yeah it blows) If I cut in an after market filler into the top hose does this make it an open system?

Thanks
Kenny
Are you talking about getting one of those deals from Summit where you more or less splice a radiator cap into the upper radiator hose? If so yes that would technically make it an open system but I don't think that's the proper way to do it.
 
I got a kit from prestone to splice a cap in the upper heater hose. Got it a year ago, works great, no probs yet. Made doing coolant flushing a breeze.
 
I think that the closed system works better than the open one I have, the temp seems to stay consistant
 
oops, misread that as "filter".


The difference between open and closed systems as I understand it are this.

Open system breathes to overflow bottle through the cap, which is open to atmosphere and burps itself as heats and draws fluid in as it cools.

Closed system does not breathe. the cap is on the reservoir and the reservoir is pressurized. Any air in the system is supposed to be trapped in the reservoir, but that never seems to work out.
 
BruceB83 said:
I don't have any cooling issues out of my '87 with the closed sytem since I have replaced the t-stat, water pump, hoses, radiator, and flushed it. It works as it should.
Thank You


1985xjlaredo said:
I think that the closed system works better than the open one I have, the temp seems to stay consistant

And Thank You.


I dont understand how these people neglect or fail to maintain the closed system and then say it sucks and needs to be swapped to open. If you overhaul everything in the closed (since you want to anyway) it will work just fine. My temp stays at a steady 185 degrees with the closed system and a 195 thermostat all year round.
 
mine also works fine on my 89 after a new radiator, water pump, and expansion tank. when it was new to me in 1990, it had overheating problems in the summer when stopped in traffic. when the radiator and water pump finally went and were replaced, i never had an overheating problem again.
 
kenny811, have you even tried to do a back flush or any type of maintenance to the system
 
88XJSport said:
Thank You




And Thank You.


I dont understand how these people neglect or fail to maintain the closed system and then say it sucks and needs to be swapped to open. If you overhaul everything in the closed (since you want to anyway) it will work just fine. My temp stays at a steady 185 degrees with the closed system and a 195 thermostat all year round.

It's just because they are a little more prone to problems. But not entirely...both of my 95's I've had/still have one, have had overheating problems too. Both different issues. I think the biggest pain (if you consider it a pain) is having to "burp" the closed system. Alot of people don't know how or just don't do it and then biT#@ when they have overheating problems because there is an air bubble trapped in the system. But don't think the open system is flawless because as I said, I've had 2 of them and both had their issues too.
 
The plastic bottle is prone to cracking and leaking.

That's why i switch all my XJs. I put a section with a Radiator pressure cap in the upper radiator hose, removed the coolant bottle, ran heater hoses from the core to the thermostat housing and water pump by-passing/eliminating the heater water control valve.

The two most important things to improve the cooling was flushing the heater core with a garden hose and house pressure and installing a fan shroud. The last two (very distressed) XJs bought were at auctions (usually $50) it is amazing, but both of these were missing fan shrouds.
 
Last edited:
Boatwrench said:
The plastic bottle is prone to cracking and leaking.

That's why i switched.

True, but the fact that they are usually 15-20 years old have something to do with it. You can always replace the reservior for $16.
 
they are known to fail in as little as 1-2 yrs.....
I hate the closed system.....stupid plastic bottle is like a time bomb waiting to strand you on the trail or road.

Sure you can carry a spare but why not put that $30.00 into a inline filler neck and be done with the fawking mess???
People are too sentimental about the closed system,I'll see you on the trail with a blown up "green turtle"....

don't get me stated on how much easier it is to do a coolant fill on my closed system because it doesn't need burped.
 
any part can fail leaving you stranded on the road.

i have never had the expansion tank fail and leave me on the side of the road.
1989, daily driver since 1990, 226k miles, never standed on the road.
 
Wow, it seems some like the closed system, and some dont. I cant change the raidator right now, so I can either cut in the filler can to the top hose, or install a knew pressure bottle. 6 of 1 1/2 dozen of the other. When the closed system worked I never had a problem with it. The cap on the bottle went bad and so this is where I am with this. Thanks for all the replies, I really enjoyed reading them all.
 
The best solution that I have come across is to switch the radiator out and replace it with a 93+ radiator. This gives you the more reliable open system. It's completely bolt in, but there are still a few things you need to change. Get a 93+ heater control valve and about 3ft of heater hose which I belive to be 5/8". With the swap you lose the sensor that turns the fan on when the jepp gets warm, so you need to hardwire the fan to a switch or get a grand cherokee thermostat housing with a sensor and wire it to a relay. This is one of the best upgrades I have done to my jeep.
 
89xj said:
any part can fail leaving you stranded on the road.

i have never had the expansion tank fail and leave me on the side of the road.
1989, daily driver since 1990, 226k miles, never standed on the road.

X2 dude...

outlander said:
they are known to fail in as little as 1-2 yrs.....
I hate the closed system.....stupid plastic bottle is like a time bomb waiting to strand you on the trail or road.

Sure you can carry a spare but why not put that $30.00 into a inline filler neck and be done with the fawking mess???
People are too sentimental about the closed system,I'll see you on the trail with a blown up "green turtle"....

don't get me stated on how much easier it is to do a coolant fill on my closed system because it doesn't need burped.

Jesus dude...breathe a little. I'm not sentimental about the closed system at all...I could care less. That is what's on my Jeep, so like anything else, I PROPERLY MAINTAIN THE SYSTEM, and I don't have any problems out of it. I don't know anybody who has had more problems out of their closed system than their open system. As I've said, I've had 2 closed and 2 opens....problems out of 3...1 closed and BOTH OPEN SYSTEMS.

I was trying to educate him so he doesn't come on here and read some horrible story with a negative attitude towards the closed system (probably written by somebody like you) and think that if he doesn't go convert his cooling system that he will be left broken down on the "trail with a blown up green turtle". People don't start complaining about them until AFTER the problem has started AFTER they could have prevented the problem. That is why you check out your vehicle before you go on the trail. That will eliminate most of your problems.

:huh: Your last sentance doesn't make any sense. A closed system does need to be burped. What?
 
I meant open system...
....every time this topic gets brought up it is the same thing:banghead: .I stated my opinion on the closed system,that makes me a bad person?

ok lets put it this way.If you like to throw money,time,and energy into the closed system it works.....

if you are like me and are tired of "maintaining" the closed system which is prone to boiling over and losing coolant and possibly overheating your motor switch to the open system.
 
I too prefer the open system for my trail rig and my daily driver. I am fixing up an 87 on the side and I am going to keep it a closed system since I am not going to spend the money on replacing the system. I know that it has a thermostat problem, its stuck open so I am gonna replace it when when I get back from a c school
 
Back
Top