Metlic53

Can I take my thermostat out?
My 90 jeep keeps getting hot while offroading and just sitting there it will run up to 240 then I gotta drive down the road and let it cool off until I can go through some more mud. Can I take the thermostat out and run it like that, it could be sticking since I've never changed it. Will taking that out hurt anything? Till winter of course.
It's hott here in texas

NorCalJeep

Pop it off. Just means coolent will run all the time. When i got my Jeep that PO didn't have one in. Went half a year till I discovered why it ran so cool.

kidrock666

band aid fix tho i would have thought, you should find out why its running so hot....

KJamesJR

I just bought a t-stat cause either mine is stuck open or nonexistent. Running so cold.

My opinion... Better to be running at operating temperature, than too hot or cold.

Cherockee

No, you should not remove it, replace is with a new correct temp t-stat and fix your clutch fan. Better also check that electric fan too.

Lead Foot

You do not want to run the 4.0 at a lower temperature by taking out the t stat. The computer will never switch to open loop mode, you will get horrible mileage. They also say the fuel doesn't properly atomize as designed at a lower temp.

Is your mechanical fan shroud in place? These are known to go missing and will cause your jeep to overheat if not equipped.

That being said, is this in the advanced tech section because removing your t stat is advanced? Also, have you tried searching?

Rinkor16

I would investigate and figure out why your engine is running so hot. Short term, removing the thermostat would work but I wouldn't go long like that.

ktmracer419

find out what is wrong with your cooling system.

is your electric fan coming on?

Metlic53

Open loop is a myth go do some research. Move this thread into another section if it's in the wrong one. I've never had a shroud on my 97 or 90 and they have always ran cold, I run a 160 t stat, colder the better, it's gonna get up to 200 no matter what anyway. Maybe the shroud would help but prob not much, 2 yrs without it and it's been fine till now, I suspect stuck t stat. Running without a t stat isn't going to hurt anything, it's 110 degrees here in the shade, just hearing your opinions.

Metlic53

Electric fan is fine, prob stuck t stat

Metlic53

Thanks I was gonna run it for a few days and see if it heats up while off roading

jeff2285

if you think open loop is a myth pick up a chrysler scaner and look at the difference in fuel ratio between open and closed loop. it needs to get to NOT to go into closed loop

RTorrez1

I live in South Texas and I run a 195 deg T-stat all year round with out a single problem If you cooling system is working correctly you shouldn't have to change your t-stat back and forth.
BTW, When you run with out a t-stat all you are doing is circulating the hot water and not allowing it to cool down. That what the t-stat is suppose to do, Give the coolant time to cool down.

tjwalker

195 degree stat. Buy it from Jeep for the best reliability and temperature control on the 4.0; I have replaced more stats than I can remember and I will not use an aftermarket stat any longer. Some work okay, but many do NOT.

Whenever you have a cooling system issue, time for analysis and replacement of whatever may be contributing. Cooling system parts are both INEXPENSIVE and EASY to replace. Best money you can spend for your XJ.

Metlic53

well i took it out, and closed and open loop is controlled by the o2 sensors, and with it being over 100 degrees out here it gets to 195 within minutes with or without a t stat. it was still overheating and that was due to my pulley being stuck which i didnt know, it exploded last night while i was going through a mud hole, put a new one on and she runs her normal 190 through the trails now, if it circulates hot water then wouldn't it get above 190? i ran for an hour and the guage never hit over 210 so i'll be fine without my t stat i believe. If it starts running weird then ill put it back in but i doubt it will being a renix, it drives the same when its hot as it does when it first starts cold.