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Need help with cooling system

matt6669

matt6669

NAXJA Member # 1602
Location
West Milford, NJ
Ok here goes

About a year ago I replaced the radiator, water pump, rad cap, and thermo due to my radiator being filled with rust.

I replaced all of that and then didn't drive it for about a year due to a electrical problem.

Well I finally got the jeep back on the road and now I have luke warm heat.

If I grab the lower rad hose its hot which its suppose to be.
If I grab the upper rad hose, its hot as well, which its not suppose to be if I understand correctly.

If I grab the top hose for the heater core that runs along side the valve cover that too is boiling hot.
Lower heater core hose not hot

The jeep stays at 210, will not go over 210, never had a over heating problem either.

If I take the upper rad hose off where that hose and the heater core hose meet at the thermo, I get steam which also isn't good.

Question
Do you think I have a clog somewhere that isn't letting coolant go to.
Or do you think I have air in my system somehow.

This is all on a 98 Chero.
Thanks guys
M
 
I would flush the system, remove both heater hoses near the tstat and using a garden hose alternate between the two, DO NOT hit the heater core with full pressure from a house hose, the system is made to run at 18PSI, most house hoses are 50+psi and higher and you will blow the heater core out, messy. Just shoot in one then reverse it, till the crud starts coming out then continue. You can also dump some white vinegar in there and let that work for a while, I'd heat it in the microwave till it's hot then dump it in one of the hoses and let if sit for a while. Then go back to the flushing.
 
heh hmmm i wonder if I hurt my heater core a year ago when I was flushing it out oppps I might still be replacing it if thats the case. Anyway to tell if you damaged it??

I also think that my rad cap is malfuntioning. I have one of the ones with the pressure release cap which If i understand correctly, if you flip the thing on the top it should release the pressure into the overflow bottle that way you can take the cap off it the coolant is still hot. Well that doesn't happen when I do it. So I am going to replace it since it got all rusted up.

Will flush the heater core like you said as well and see what happens.
Thanks a lot for the fyi!

Matt
 
matt6669 said:
heh hmmm i wonder if I hurt my heater core a year ago when I was flushing it out oppps I might still be replacing it if thats the case. Anyway to tell if you damaged it??

I also think that my rad cap is malfuntioning. I have one of the ones with the pressure release cap which If i understand correctly, if you flip the thing on the top it should release the pressure into the overflow bottle that way you can take the cap off it the coolant is still hot. Well that doesn't happen when I do it. So I am going to replace it since it got all rusted up.

Will flush the heater core like you said as well and see what happens.
Thanks a lot for the fyi!

Matt
Click to expand...

If you damaged it your feet would be all wet...
 
oh ok, my feet are perfectly dry so its not blown out then :)
Will post back up, I am going to replace the t-stat and the rad cap tomorrow and see what happens.
M
 
Your heater in hose is hot, but the out isn't. Your heater core is still blocked.
X2 on this If only half the core is cloged. You will get a good flow but cooler air.
Does the 98 have a blender door? Do a search for same. There is a good right up somewhere about it. Plus a good wright up about a quick fix. If bad. Quicker then pulling the dash anyway.
 
Sombody on ebay sells a kit where you hack into the housing (in place) instead of pulling it all apart to replace a broken blend door. To check out the blend door, you have to pull off the actuator and turn the blend door shaft to see if feels broken or changes the heat. Not an uncommon failure mode. The actuator could also be bad, which is easier to replace. The blend door changes the air flow to go over the heater core or not.
 
Heater coolant control valve? Is the heated coolant being allowed to enter the heater core? No coolant going in, no heat in return hose?
 
The newer jeeps don't have a mixing valve that I'm aware of, they get a steady coolant flow thru the core anytime the engine is running, at least I'm pretty sure of that, I'll have to look at the fsm as I don't remember for sure and even then it gets some crap buildup in there.
 
If the blend door were bad, wouldn't the return line from the heater core still be flowing hot coolant from no airflow across the core? I'm leaning toward blocked core as well.
 
ok im just straight up confused. I went out and bought a new rad cap. I installed it and started the jeep. Jeep got to operating temperature but some reason my coolant isn't going into my overflow bottle. When I go to take the rad cap off it comes flying out of the rad cap. And for some reason, tonight, the fluid wasn't even luke warm, it was still freezing cold. I can now think of only two things. My brand new t-stat is bad, or my brand new water pump is bad.

Grrrrrrrrrrrr everything worked fine before i replaced the radiator, i shouldn't of touched anything since it technically wasn't leaking bahh
 
matt6669 said:
ok im just straight up confused. I went out and bought a new rad cap. I installed it and started the jeep. Jeep got to operating temperature but some reason my coolant isn't going into my overflow bottle. When I go to take the rad cap off it comes flying out of the rad cap. And for some reason, tonight, the fluid wasn't even luke warm, it was still freezing cold. I can now think of only two things. My brand new t-stat is bad, or my brand new water pump is bad.

Grrrrrrrrrrrr everything worked fine before i replaced the radiator, i shouldn't of touched anything since it technically wasn't leaking bahh
Click to expand...

check your belt path and tightness, you could be spinnng it the wrong way. But I'd tend to go with belt tension, your best guess at 190lbs is probably closer to 60lbs.
 
RichP said:
check your belt path and tightness, you could be spinnng it the wrong way. But I'd tend to go with belt tension, your best guess at 190lbs is probably closer to 60lbs.
Click to expand...

I do get a little squeak at startup but I don't think the tension is too lose to not be spinning the water bump, but I will tighten it up a little bit to make sure that I am flowing water.

I don't think I have the belt reversed otherwise the upper rad hose would probably be collapsed and it isn't, but I will double check that as well tomorrow.

Keep em coming, I think I am going to take out the t-stat tomorrow and then put it back together and see what happens since then it will always be in open and see if I get better circulation. Then see if the heat improves.

I am also going to flush the heater core by itself tomorrow as well.

M
 
As far as belt tension is concerned, in my case mine started not charging when it was cold and the meter would go to -0-, 6 turns on the adjuster solved that problem till I could stick the gauge on it and crank it 6 more times to get it to 170lbs.
 
well it gets even more retarded.
I am convinced that my coolant isn't circulating through my system but I don't understand how my motor isn't over heating.

It would seem that when i get back home from vacation, I am going to have to tare apart, the whole front end of this pos and redo everything that I just redid.
OH yippie
 
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