Overheating, everthing brand new.
09-03-2013, 08:47 PM
#1
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Location: so cal
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Year: 1990
Model: Cherokee
Engine: 4.0
Overheating, everthing brand new.
Hello all, I have a 1990 Cherokee 4.0. It's runs hot, if I let it idle it runs cool, and if I'm driving on flat ground its fine, as soon as I hit a hill it slowly climbs. Even if its parked in the driveway, an I hold rpms at 2500 in park it slowly climbs to the red. As soon as I let it idle, it cools down. Now I have brand new aluminum 2 core radiator, second radiator I have installed. Brand new t stat, waterpump 2nd water pump. All new hoses, new sending unit. Even did a block test, came back clean. And it is converted to open system.
I really hate to start a new thread, but this has me stumped and I am a mechanic. And I have checked temps with a oinfared gun, and it is getting hot. And one more thing, it seems to be getting worse, I use to be able to drive up hills if it was 70 degrees outside, and it would be fine. Now I just took it out Sunday morning it was cool outside, and it got hot, not to the red, but would have if I didn't pull over. O and it is converted to 2 electric fans, and yes there on.
Thankyou.
I really hate to start a new thread, but this has me stumped and I am a mechanic. And I have checked temps with a oinfared gun, and it is getting hot. And one more thing, it seems to be getting worse, I use to be able to drive up hills if it was 70 degrees outside, and it would be fine. Now I just took it out Sunday morning it was cool outside, and it got hot, not to the red, but would have if I didn't pull over. O and it is converted to 2 electric fans, and yes there on.
Thankyou.
09-03-2013, 09:39 PM
#5
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Model: Cherokee
Have you burped the radiator?
Raise the front end, with the cap off let the motor get up to temp. You Could have a large amount of air in your engine. And are you electric fans pulling air in the correct direction?
Raise the front end, with the cap off let the motor get up to temp. You Could have a large amount of air in your engine. And are you electric fans pulling air in the correct direction?
Last edited by rockstomper92yj; 09-03-2013 at 09:41 PM.
09-03-2013, 09:48 PM
#7
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Year: 1990
Model: Cherokee
Engine: 4.0
Turbo, I have not done a coolant pressure test, but have done a block test. I have done a compression test, and 3 cylinders were at 40#. Now in all the years I have been working on cars, I have never seen low compression cause this problem. Another wierd thing is that it takes 90# for a cylinder to fire. And it runs like a top and just passed comifornia smog. But I will say, I am starting to think that is my problem.
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09-04-2013, 11:13 AM
#12
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Year: 1991
Model: Cherokee
Engine: 6 inline
Ac condenser clog maybe? . Never hurts to check if u put in the thermostat in correctly. Sometimes it might limit the amount of coolant flow. Umm right coolant/ water mix? . Just throwing stuff out there maybe u didn't check lol