1989 cherokee overheat issues *help*

[JeepTrouble]

It's not the thermostat, it is not the radiator, these things have already been replaced.
HELP!!!!

I can drive a block down the street and the damn thing is up to 250 degrees! drive a mile and it had better be a one way trip! Any other ideas anyone?

*rips chunk of hair out of scalp and stares at it laughing hysterically*

[fredjacksonsan]

I take it the same problems exist even after the thermostat and radiator replacement. How about the water pump? If the fins on the impeller are extremely worn, the circulation of the coolant could be reduced. (And I hesitate to mention the temperature gauge, since it seems by "one way trip" it will boil over in a couple miles)

What I'd to do check, is to start cold, with the radiator cap off. Let it idle while keeping an eye on the temperature. Once it reaches operating temp, the thermostat will open and you should see some flow across the radiator. If there is no flow, then there are 3 things I can think of why:
1) Bad impeller/water pump
2) Blockage somewhere
3) New thermostat faulty or installed backwards.

Hopefully that will help. Post more descriptions and maybe be able to help a bit more.

[Saudade]

What Fred says.

But the earlier XJ's had a closed cooling system that's a PITA to fill. Air can get easily trapped and prevent you from completely filling the system.

When the engine is hot, CAREFULLY, feel the upper hoses and the top of the radiator. Do they feel hot? When you rev the engine, can you see coolant flowing back into the coolant bottle?

Does your elect fan kick in?

Make sure your serpentine belt is routed correctly.

[fredjacksonsan]

Ah, so. Forgot the possibility of an air bubble. Easy way is to drive the vehicle so the front end is about 1 foot higher than the rear; that way any bubbles will rise to the exit. (Just be sure to watch the coolant level)

Good catch, Saudade.

[Dansjeep89]

My 89 cherokee also had an overheating problem earlier this year... I pretty much had to have everything replaced.

Here is the list:

Water Pump ($160)
Radiator (3 row $130 labor $50)
Thermostat ($65)
Coolant tank ($30)
Head (used head $100 labor $250)

So, thats what it could be looking like for you...

Good Luck,
Daniel

[89ltd]

I also have an 89, when I bought it, it would over heat, so first the thermastat change to 180 (old stat was in backwards, spring part in the housing) then it was fine until winter then not enough heat. I figured, the first stat was in backwards , maybe that is why it failed and put a 195 back in. Now no overheating and the heat was great until the spring came..... Back to over heating again, not a lot, but to much, changed back to 180 and its fine again so I guess I will change it each season like my grandfather used to do so many years ago. I have to much money invested in the POS cooling sytem to change it to the 92 version.

[89ltd]

don't let it get to hot or you will blow the head gasket or worse..

[89ltd]

I also changed the clutch on the fan, maybe that helped, but I don't know for sure, good luck.

[mrbill3]

A couple of things to ponder. A lower temp. t-stat will not make your engine run cooler, it will only open earlier. Next is that most replacement t-stats for the XJ do not have a bleed hole. If you carefully drill a bleed hole in the body of the t-stat (besure it is in the area that will be in the t-stat housing) you will not have to "burp" it. The procedure I use (when there is no hole and I don't drill one) is to disconnect the upper hose at the t-stat housing fill the radiator through the hose as much as you can, re-attach the hose, fill the palstic tank, start and let it idle until it gets to just before the red area on the guage (if it does not overheat you're fine)shut it off and carefully release the pressure at the plastic tank. Then carefully feel the upper hose at the t-stat housing to see if it is hot and disconnect the upper hose again. Refill the radiator through the upper hose again and the pour as much as you can into the t-stat housing (the t-stat should now be open) then refill the plastic tank. Last re-attach the upper hose and start it again and the problem should be gone!

[89ltd]

my 180 stat runs cooler than my old 195, 15 degrees to be exact.....

[Stick89]

Do the swap,it will cure the overheating prob.....I went through 2 rads before I swapped to the open....It is a direct swap,there should be NO MODIFICATIONS AT ALL..The only differance is that you will have a filler neck/Radiator cap....and if you want you can wire the aux fan to a switch n turn it on when ya wanna....