XJjimbo

hey everyone i have a 01 xj and it over heated on my to work was only driving about ten minutes when i noticed the gauge and check gauge light. the waterpump and t-stat, housing and temp sensor were all replaced a couple of months ago. so i thought maybe the thermostat stuck closed and replaced it. after letting the jeep run and warm up for a bit it didnt show any signs of running hot or overheating . so i got in to take a test drive and i wasnt out the driveway and it pinned with light like it was over heating, any thoughts or suggestions what might cause this?

Bbasso

start with this: https://www.cherokeeforum.com/f2/you...system-144771/

NWhunter

Did your burp the system? When ever you replace a waterpump or thermostat you need to burp the system from any air. Also hows the fluid looking? Maybe a flush is in order.

SpruceJedi

Temp sending unit? I am not sure how to test to see if those are working other than replacing it.

Be really careful with the temp of that 01 engine. Its really common to crack the head when they overheat. I know from experience, just replaced mine. Hopefully you get it sorted out real quick. monitor your fluid levels really closely, if you start losing coolant unexpectedly in the future I would start investigating. Good luck!

Radi

Where'd you get the replacement temp sensor? Do you still have the old one?

Later year temp gauges, like yours, are not linear. When they cross a certain threshold the PCM slams the needle full-right to get your attention and turns on the light. If your replacement sensor isn't correctly matched it may be crying wolf.
BUT- you also have one of the heads prone to cracking when overheated, so do NOT assume this is the case until you are certain it really isn't overheating! An infrared temp sensor aimed at the t'stat housing should tell you.

Bbasso

no need for "burping the system"
it's an open system and if it's working properly it will take care of itself. just add fluid if needed.