So my 94 xj was running a little hot at about 210 and I wanted to bring the temp down a bit so I changed the thermostat from the oem 195F to a aftermarket 180F and flushed the coolant. I also put on a new rad cap b/c coolant was overflowing out of the cap...the new cap solved that problem. But now the temp gauge gets up to 260 befor even idling for 10 min. I'm thinking I messed up on the flush and refill and got air in the new coolant. How do I go about purging the air out if there is no purge valve on these jeeps? Also, could there be any other problems I should look into as to why the jeep would suddenly start overheating like that. The engine isnt even hot nor is the radiator cap but the temp gauge still keeps climbing!

 

210 is actually the normal operating temperature.

 

if theres air then itll cycle around so check the fluid levels once in a while and youll be able to get the air out that way.

your not running too hot anyways

 

Well that's not the problem anymore. Iv'e already flushed the coolant and added new coolant and before 10 min of idling is up the temp guage reads 260F so my question is how do I "burp" the cooling sytem?

 

http://www.lunghd.com/Tech_Articles/...BurpAirMod.htm

 

start it up with the rad cap off, turn the heat on full blast, let it run add coolant into the rad as needed, do this for 10-15 mins, pop the cap back on and check it out. Repeat as needed, should work for you.

 

Yep,that should get it, with the cap off the t-stat will open and let the cioolant flow, your level may go down some just top it off as needed. you can tell when the t-stat is open and closed by the flow

 

There is a very easy way to "Burp" the cooling system and its only about $3.99. Get the "Prestone/Professional Flush and Fill Radiator Cleaner Kit" from AZ or almost any other car parts store and put the "T" in the top heater hose then fill with coolant and run motor with heater on and you can bleed the air out by the "T" valve. Part #AFKIT from AZ ..Tj

 

dont get the kit i here nothing but bad storys of the "t-fitting" breaking off into your coolant.

all you have to do to "burp" the system is start up with the rad cap off heat on HI let the eng warm up and then with your hand squeeze the coolant lines. you should see a rise in the level and some air bubbles come out. then add more coolant. simple but watch out for the fan and pullys!

 

What could be easier than letting it idle with the rad cap off.....when coolant starts to flow out the neck of the rad, put the cap back on. For the next 2-3 days, ENGINE COLD, remove rad cap and add coolant as needed 'til coolant level remains in the neck of the rad. Check the level in the overflow bottle also. Any extra fittings r just more leak possibilities.

 

Sounds like a pretty easy fix then. Hopefully it solves my problem. Thanks for all the help guys!

 

park it so the nose is pointing downhill, make sure your overflow is full, turn it on and crank the heater. Pay attention to the reservoir and add more fluid as necessary. I overfill it when I think there might be a little air in the system and park downhill as often as I can. Let it idle while I get everything together.

 

Thanks Jac but I fixed this a while back. Turned out there was a lot of air and not enough coolant. So it took a combination of burping and adding coolant

 

BTW, welcome to the forum!!

 

from all the learnins i got from school air goes to the higest point parking the nose down would cause the air to remain in the rear of the block the front would need to be higher than the rear making the radiator cap the high point the vechicle needs to be ran until the thermostat opens then fill with coolant raise the idle causing the water to go down in radiator install rad cap while idle is up fill colant bottle and drive then recheck over flow bottle your done