so i did a rad flush on my jeep cause the water looked rusty and also installed new thurmostat 195 degree. when i drive it stays at 210 or lower without aux fan but when i come to a stop or sit ina place for awhile the temp goes up to just under the third bar (95 style cluster) 90 degree day with a/c on. if i turn the heat on it seems to help it cool down. and yeah once it gets to 218 the aux fan kicks on so its not that.

Let me know what it could be shes only got 88,000 miles still gotta lotta life left not tryin to kill her over something simple. thanks guys

 

i think its just old mine did the same so i jerry figged it so its always on as long as the key is in the ignitio, and my temp has never been above 200, also what type of enviroment i found that when i drive through the desert when its 95 its runs cooler as opposed to the humidty of say the east coast.

 

yeah im from pittsburgh its very humid here. well if thats the case ill wire up some e-fans

 

did it overheat before the flush? are you sure there isnt air trapped in the system?

 

it still ran high but not as high. if there where air in the system how would i get that outtta there?

 

typically when it overheats a bit in traffic or low speed it's the Clutch driven machanical fan's Thermal clutch.

they're cheap and easy to replace. Don't even need to pull the belt just the fan shroud and aux fan.
Many go with one from a ZJ that pulls more air when the clutch locks up than the stock one does. It's about the same price too.
I went with the HD ZJ fan and it's never gotten over 210 no matter what.
If you go with the ZJ HD fan there;s only one kind to get only from NAPA.
DO NOT get the Max Kool version or it won't fit.

For the HD one ONLY GET NAPA part#272310.

Your only other prob could be a failing water pump from all that crap in the system, but I'd replace the Thermostat and fan clutch first since the stock clutches only really last 5 years at best, kinda like Jeep's Trac Lok LSD lol.

 

the only xj that are effected by trapped air are 87 thru 90 renix with closed systems

 

I have also heard this

 

FWIW, '91 up could possibly have a problem if the rad cap malfunctions.