hey i'm tyler. I have a 89 jeep cherokee laredo. The engine keeps over heating though. i replaced the radiator, thermostat and water pump. and its still doing the same thing. No signs of a cracked head. But diffiantly up for suggestions

 

What about replacing the cap on the pressure bottle... Maybe the bottle has a crack in it?

 

Hi tyler and welcome
I have a 1989 cherokee also and had similar problems back when my dad owned my jeep and went nuts figuring it out i did the same things.
1-New theromostat
2-waterpump
3-flushed out the system
4-new water bottle (there was a slight leak around the cap) don't try to fix it replace it and a new cap.
5- sender switch for electric fan
6-and finally what fixed it was the clutch fan.
the clutch on the fan went bad and there was no resistance so the fan never got up to speed with the engine causing not enough air flow thru the radiator.
keep in mind this is a closed pressureized system when you refill your system get all the air out of the system by slowly squeezing the radiator hose with the cap off and cold engine. you will see when it looks full, slowly squeeze the radiator hose and you will see air burp thru the bottle and then keep adding coolant till you feel you got all the air out. it will take a while. if you fill the system and you close the cap there is no way for the air to escape and you now have a air pocket not allowing the coolant to flow properly.
let us know how you made out.

 

My sister had a lot of problems with her 90- overheating. I finally bought a newer radiator with a radiator cap in it and did away with that plastic bottle. Never had anymore trouble with it.
Going to do the same with my new 90
clint

 

It might be the clutch fan. But the fan is blowing air. But can it blow air but not hard enough

 

I think you have an air lock. Just have to work it out like suggested and keep an eye on your resevoir level when you think you have it worked out it may need some added after a little driving or run time.

 

Give that man a cigar!
Yes , if the clutch hub has failed the fan will not move enough air to cool the system. ALSO, if you have A/C and the condensor which is mounted in front of the radiator is plugged up with debris and leaves and nasty bugs it will cause the engine to run hot. No air will be able to reach the radiator. Do you know anyone who has a thermal laser temp gun. Checking the inlet and outlet hoses on the engine when it is running and hot will help you to see if it is cooling correctly

 

[QUOTE=TheGreatGazoo;280662]Hi tyler and welcome
I have a 1989 cherokee also and had similar problems back when my dad owned my jeep and went nuts figuring it out i did the same things.
1-New theromostat
2-waterpump
3-flushed out the system
4-new water bottle (there was a slight leak around the cap) don't try to fix it replace it and a new cap.
5- sender switch for electric fan
6-and finally what fixed it was the clutch fan.
the clutch on the fan went bad and there was no resistance so the fan never got up to speed with the engine causing not enough air flow thru the radiator.
keep in mind this is a closed pressureized system when you refill your system get all the air out of the system by slowly squeezing the radiator hose with the cap off and cold engine. you will see when it looks full, slowly squeeze the radiator hose and you will see air burp thru the bottle and then keep adding coolant till you feel you got all the air out. it will take a while. if you fill the system and you close the cap there is no way for the air to escape and you now have a air pocket not allowing the coolant to flow properly.
let us know how you made out.


I have had a lot of that, replaced everything. Noticed that when it overheated, the bottle 'cap' was loose (skipped a thread) therefore losing pressure. So I just put a hose clamp on the cap to keep it on. That works. Simple fix!