So it seems that with every problem fixed another on shows its ugly face. Anyway i just did a head gasket on my jeep about a week ago everything went smooth and i did everything to spec(torque, head plained etc). On the re install of everything i decided to bypass my heater core because its shot. I also hooked my electric fan to a toggle switch.

So the problem im having is on these warmer days 80+ degress the jeep likes to over heat

For the first 5-10 miles the temp slowly creeps up to the first mark on the gauge. Another 5 miles or so it creeps to the 210 area. It will sit at 210 for a good 5 miles and then all hell breaks loose it slowly creeps to the 260 mark and will not even think about going down unless you shut it of. Mind you im running no thermostat, bypassed heater core, year old radiator, year old water-pump, recent radiator flush. Dosnt appear to be any blockages because when i removed the cap on the expansion tank there is great circulation. My driving consists of mostly 55mph.

Someone help me.

Id like to convert to a open system but keep my radiator as its not old and doesn't leak. List of parts i will need?

 

Sounds like air in the coolant.

 

X2^^

 

Also, no T stat can actually cause the coolant to flow "too" fast through the radiator to shed heat, renix era will will run real fat till temp reaches "normal"

 

Best way to burp the system? i know its on here just to tired to search

 

And why are you not running a thermostat?

Damn someone beat me to it.

 

 

here is one.

https://www.cherokeeforum.com/f2/bur...-system-19001/

 

No thermostat because when i did the head gasket the one i took out was pretty bad so when i put it back together i didn't have a new one at the time and neither did the local Napa so it was only meant to be temporary. But i did pick one up on the way home tonight so i will be installing that in the am and burping the system hope that's all it is.

 

How did you know it was bad? How did you test it?

 

No i did not test it but being it looked to be damn near original and with the jeep having 227k miles on it i figured it wouldn't hurt changing it. Just local auto store didn't have them in stock had to wait for one. tho i have ran many vehicals in the past without a thermostat and never had an issue

 

With the stock radiator, if you dont have a thermo, it will either over cool, or over heat. Which would lead to bad mileage and increased wear on the deck of the head. Thermostats are there for a reason. Use them.

 

So i started by draining out as much of the old brown looking antifreeze as i could, put in a new thermostat, put the back of the jeep on some ramps, filled the radiator with 50/50 from the top hose, replaced hose, filled overflow started the jeep. Let it idle with the cap off the tank till it came up to 210 area it continued to creep past it so i shut it off, as soon as i did it shot out of the overflow like a geyser for a couple seconds. after that i refilled the tank let run for another 10mins at idle started to creep past 210 again so i shut it off this time no geyser but it did burp quiet a bit out the top. I put the cap back on let it idle for 20 mins stayed right at 200 degrees took it for a short drive dropped down to 180ish brought it back let it idle came up to 210 but didn't go past it. So i think i may have fixed it, I have to run to town in back about an hr trip so well see how she does. Its 90 degrees outside today so if she don't over heat then i would think everything would be kosher.

 

Sounds like you may have for the gremlin out of the radiator.congrats

 

Try this. Go to Napa and buy a new cap for your coolant bottle. Part number 703-1396. Yours is obviously not holding pressure. Don't get another stock type chinese crap.