88 closed cooloing system question

[scrap_iron]

I have an 88 with the old closed system and the guy that sold it to me just replaced the radiator last year so I don't want to convert to a open system at this time. I just have a couple general questions.
Not having a normal radiator cap, is there any pressure relief in it, to release the pressue if it should ever overheat ?
I don't see any fill level marks, so I keep the tank on the firewall about 1/3 full...sound about right ?

[4x4grey88]

You should fill your resevour level about 1/2 full that will leave room for expansion/heat. The cap on the tank will relieve pressure in the even of over heating.

I have a 1988 Cherokee also but am changing it to a open system. I have had intermittant overheating problems, I 'burped' the system and after changing out the thermostat the temp probe, and the water pump I still see overheating.

I did some research and found that the stock Cherokee radiator only uses a two pass rediator. I purchased a 1992 three pass open radiator ($135.00 delivered) and no longer have any overheating problems. It was a simple change out and need a few modification (like the heater valve and resvour for a open system). Oh by the way the two pass redaitor was not clogged either.

[Saudade]

If you remove the cap and look down inside the bottle, you'll see something resembling a small plastic tube (but it's not hollow). It will look like it has a small section cut from the top making a step. That's the level indicator. When cold, coolant should be above the step but below the top. Roughly, it's halfway as 4x4 suggests.

I too have an '88 with the original closed system. It is a bit of a pain to burp. However, once done, mine seems to perform just fine.

[invisiongrafix]

I too have an 88 with the closed system. When I purchased the Jeep one of the things I was told is that the radiator was recently replaced. Experienced overheating problems galore. Changed everything, some things twice and three times. Made some calls and found the garage that had done some work on the Cherokee. Guess what? The radiator was known to be bad but wasn't changed. A new radiator and everything is good.

[scrap_iron]

Thanks for the response....I also was wondering, if I wanted to add an aftermarket temperature gauge and still have the idiot light, is there a place to add another temperature sensor for the gauge on the 4.0 engine ?

[Stick89]

I went thru 2 rads,before I finally realized that the closed system is the worst designed cooling system ever devised.
IMOHO....burping is for small babies,I swapped mine out to the open system bout a year n a half ago and have nothad any problems what so ever.
Ther are problems with the closed system,as in the pressure bottle cap and O ring.Once it over heats,the O ring is usless....and if the temp gets high enough to cause a boilover,the t stat is wasted.
There are those who will swear by the closed system,never had a problem and sso on,but I really believe that that particular system is usless.Read somewhere awhile back that someone had posted a "former"
JEEP engineer and his reply on the closed system was that it was one of the most ridiculous systems EVER designed.....
After I did the swap,I counted something like 13 htr hose clamps that I no longer needed.You eliminate the tubing that has something like 4 places where hoses hook to I mean thia is a nightmare to try to trace.
Spent @ $220.00 on GDI 3 core w/neck,new t stat,htr hoses,rad hoses,
and clamps.Chnged out water pump,but that was a lifetime warranty so that was free.Took my time and was completely done in bout 4 hrs.This also included a double back flush,did it 2 times,1st time got some yucky stuff outta the old rad,2nd time looked like it had the Hershey squirts.
So far I have had no problems with the system and I live in Texas,so summers ain't the coolest.I also wired the elec.fan to a switch so if I do get in traffic I can turn it on IF I see the temp rising.I also have alternate routes so I can avoid the traffic if needed.There have been a"coupla"times when I had to drive down off the e way thru a ditch to get to the service drive ain't 4 wheel great

[Candoo]

Do you have the run-down on exactly what you had to change and the steps to do it. Tonight, the wife blew the upper rad hose while driving. I went to her rescue, picking up another hose on the way ($20 later), and installed it. It was 2 miles home and just as she pulled in front of the house, BOOM like a gun, and it blew the new one. This crap system just ain't gonna work !!

TIA ..... Mark

Originally Posted by Stick89

I went thru 2 rads,before I finally realized that the closed system is the worst designed cooling system ever devised.
IMOHO....burping is for small babies,I swapped mine out to the open system bout a year n a half ago and have nothad any problems what so ever.
Ther are problems with the closed system,as in the pressure bottle cap and O ring.Once it over heats,the O ring is usless....and if the temp gets high enough to cause a boilover,the t stat is wasted.

After I did the swap,I counted something like 13 htr hose clamps that I no longer needed.You eliminate the tubing that has something like 4 places where hoses hook to I mean thia is a nightmare to try to trace.
Spent @ $220.00 on GDI 3 core w/neck,new t stat,htr hoses,rad hoses,
and clamps.Chnged out water pump,but that was a lifetime warranty so that was free.Took my time and was completely done in bout 4 hrs.

[foxy88]

i just swaped mine over today. very easy just remember to get all the parts you need before the tear down. I got a rad. from napa thats for a 92 cherokee, a rad. cap, a universal overflow bottle, 25 inchs of heater hose, and 22 inchs fuel line (for the overflow bottle feed line), also some small clamps (for the fuel line) . the new rad. will fit right in no problem. the extra heater hose is to reach the heater core since you will be removing the metal pluming instead of spliceing.

[Candoo]

I should have posted this a while back, but .......

I did the swap out and I haven't had any problems since. It works like a charm

I used the Napa parts that were listed. Most were common to the Canadian Napa #'s, some not, but they were easy to cross. The swap was very very simple. I had to get the thermostat housing directly from the Chrysler dealership as the wrecking yards didn't have one. Surprisingly, the housing was only $25 Canuck ($20 US). The original housing (get this hehe) is $80 ...... go figure!!!! The Chrysler dude at parts thought that I was totally totally nuts when I told him what I was doing, and stated that it was never going to work. Hmmmmm. I gave him my number and told him to give it to other poor saps with cooling probs, instead of trying to sell them expansion tanks. Now they'll probably put up their prices on the housing.

I thought the price on the temp sensor connector was a bit much, $26 (new). The sensor and connector is actually a GM part, for a Buick I think. If I had realized that at the time, I would have pulled one from a wrecker cheaper. The hardest part I had was getting a collection bottle to fit. I believe the one I ended up using was from an S-10 Chevy. I have A/c and the lines thru the firewall were a problem for bottle sizing.

Thanks for the help and solution to a problem that should have never been in the first place. Just real poor design on Chrysler's part.

Mark