89 overheating at high speeds
#1
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Year: 1989
Model: Cherokee
Engine: 4.0
89 overheating at high speeds
I have an 89 laredo and have done the 91 radiator upgrade. I have new water pump, hoses, radiator, universal over flow bottle, rad cap, fan clutch, thermostat housing, and have tried 2 thermostats and have electric fan on as soon as ignition is on. I have burped the system. I live in phoenix az. When it is under 95 degrees outside it runs at 200 anything over 95 degrees outside with the ac on over 45 mph it gets real hot. I don't let it get in the red. I turn the heater on and it cools down to 210. I don't no what it could be there is no leaks and I have replaced everything there is to replace. There are no bubbles in the oil and oil is not milky so I don't think it is a blown head gasket. My only thought is that my coolant bottle sits below the the rad fill neck. Is it supposed to or should it sit above it.
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Year: 1994
Model: Cherokee
Engine: 4.0L I6 MPI "Power Tech HO"
I'm guessing you have flushed out the system, made sure the block wasn't clogged, it's the only thing I can think of besides the Thermostat being clogged to make it over heat while moving.
It's not getting cool fluids circulating, there can only be a few reasons why, like water pump, thermostat, block or radiator blockage...
Have you checked your PSI on the A/C because you say it only does it when the A/C is on, maybe the Compressor is working a little too hard and its negatively effecting the engine. Compressor been lubed lately? it's an additive I think just called conditioner...
Just my thoughts on the subject.
It's not getting cool fluids circulating, there can only be a few reasons why, like water pump, thermostat, block or radiator blockage...
Have you checked your PSI on the A/C because you say it only does it when the A/C is on, maybe the Compressor is working a little too hard and its negatively effecting the engine. Compressor been lubed lately? it's an additive I think just called conditioner...
Just my thoughts on the subject.
#6
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Year: 1989
Model: Cherokee
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I moved the coolant bottle up and leveled out the upper rad hose. Drove it today and still the same thing. Even with the ac off at 65 it still wants to overheat.
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Year: 1989
Model: Cherokee
Engine: 4.0
Ok so yesterday I tried running without a thermostat and I was almost overheating at 10:00 at night so that was no good. I put a 180 thermostat in this morning and it was running at 220 on the freeway and 210 on the streets. That was when it was 95 degrees outside. Now its about 105 out so we will see what it does now. If my oil pump is bad will that cause it to run extra hot at high speeds?
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#9
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Year: 1989
Model: Cherokee
Engine: 4.0
The lower hose is the only thing I haven't replaced yet. It does feel a little soft but from what I can tell it isn't collapsing. But I can't watch it while im driving. I am going to replace it and then that is the last thing left to replace.
#12
When it gets hot you can check to see if your lower hose is collapsing by popping the hood and revving it manually. Are you sure you are putting your thermostat in correctly and is your cap the right one?
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Year: 1989
Model: Cherokee
Engine: 4.0
Its not overheating its just getting really hot I shut the ac off before it overheats and turn the heater on to cool it down. But this really sucks when its 110 outside