Thursday, October 6, 2011

Why does my 98 jeep grand cherokee continue to overheat?

i changed the radiator, the thermostat, thermostat housing, and flushed the system multiple times..i also took out the thermostat and it still overheats. the heat does not work, it just blows cold air and the upper rad hose has a lot of pressure in it after the thermostat opens. if i leave the cap off the rad then it will not overheat but i will lose fluid
Why does my 98 jeep grand cherokee continue to overheat?
1. Disconnect the heater lines at the core. Place a large container on top of the engine [higher the better]



2. Place hoses in the container %26amp; secure



3. Check the coolant. Make sure it's full.



4. Start the engine. Coolant should flow a a steady stream from one of the hoses.



5. If not - replace the water pump



6. If yes - then you may have a slight leak in a/the head gasket. Coolant does no always make its way through the crack. The pressures of combustion are much greater than the 15 PSI in the cooling system. Try to check the pressure within the cooling system. Normally around 15 PSI

18 - 20 PSI is high to extreme.



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Why does my 98 jeep grand cherokee continue to overheat?
its a Jeep....
b/c u need a new car. its asking u to kill it!!!
Sounds like could be the water pump,your getting presure at the top hose because of no circulatiom
I wonder if you changed the radiator cap when you changed the radiator. If you did not, do that, the radiator cap's pressure spring may be stuck and if it can't %26quot;pop%26quot; when the ideal temerature hits, it will create too much pressure in your system. Pressure is heat, and you will blow something soon enough like that. Also, you did not say if you replaced your water pump. If this pump is broken, it is not spinning when the engine is on, and all the coolant inside of the block is basically sitting there, getting hotter. Change the pump and the cap, this could also be why hot fluid isn't getting to your heater core
Could be the water pump...the heater not working could be a couple of things but initially it could stem from the fact that your water pump is on the fritz.



If this is the case, you definitely would want to get this fixed immediately. Not having your engine cooled would result in astronomical repair costs which, unless you love your 98 like I love my 97, would make more sense to get a new (another) vehicle versus fixing that one...mine is (thankfully) paid for, though it rides rough due to the short wheel base, it is well maintained...



I like the fact of jumping into something that'll start at the drop of a hat, run like a leopard, looks good, and is PAID FOR versus having a $500 a month note for the next 6 years!



Get your water pump checked...this could very well be the root of your dilemma!
Some cooling systems have a thermostat which is a double effect thermostat meaning that it does two jobs.

You cannot replace it with any any thing that looks the same,It must be the thermostat for that engine,taking it out will not fix the problem.

Next thing to do is to check to see if the water pump is pumping the water,one way to check is to look in the top of the radiator and you will see if the water is moving,when you accelerate the motor,the water level should drop.

Is there a bleed valve on the cooling system?.Some systems need to be bled of air in the system.This will look like tyre valve on one of the hoses.

Are there bubbles of air in the radiator?,if so,when you rev the engine,are there more bubbles?,If so then it is more than probable that you have blown a head gasket and this is what is blowing your coolant out of the radiator and that is why there is a lot of pressure in the top radiator hose.
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