SeniorXJ

So ive been noticing that my temperature gauge is reading a rather odd number under any kind of driving which I calculate to be round 150. Sometimes it will run at a normal temp of 190 to 210 & then out of the blue it will just drop down to that 150 mark & do it within a few seconds!! Other times it doesn't even get to normal running temp & just stops at the 150 mark. No matter what tho, there is no other readings other then normal running temp or the 150 mark seen here in this pic:



Only 2 things I can think of here is replacing the thermostat & if its still doing the same then get a new temp sensor. Its just so odd that it drops down to that same spot all the time so anyone with some input would be appreciated!!

Thanks!

cruiser54

Go buy a stat from the dealer. They're the best uality and keep your Jeep at the right temp. Also they insure fast warmups in the winter.

Muaddib420

My bet is temp sensor with that quick of a drop.

freegdr

x2

SeniorXJ

Someone said to me:
The gauge is not linear & the first mark is about 195° so when it does that it is because the thermostat opens up completely.

So I said back:
I though about it being that exactly, that the drop is when the t-stat opens up, BUT that's a huge drop & this being my 2nd XJ, ive never seen a running temp where that guage is in the pic!!

SeniorXJ

Anyone else think this may be a normal reading & that the gauge in the pic is actually pointing to 195 deg??

djb383

Ask yourself a ?......when the gauge ispointing at 150, how well is your heater working? If it's working good, most likely something is wacked about the gauge reading. If heater performance is poor, could be the t-stat stuck open or missing. My guess is something wacked with the gauge, sensor, or electrical connection.

Ain't no way that point (1/4 mark) on the gauge represents 195......not even Chrysler/Jeep engineers are that goofy. LOL

Firestorm500

You need to be more concerned about that airbag light being on.

Get an IR temp reader and point it at the thermostat housing when showing that temp on the gauge to see what it's really doing.

If the radiator is not icing up or boiling over, it's probably OK.

SeniorXJ

Just noticed that when I was parked with the motor idling, the gauge at that mark, & the AC on, (yes my AC works!!), that the electric fan was running, so the motor has to be at running temp if not more for the aux fan to click on,,, right??

Do u think its worth changing the stat anyways to see if theres a difference??

(Airbag fuses are pulled cause I had my 7yr old Son in the front seat)

bulrid8

Fan runs anytime the ac is on.

Firestorm500

Put the airbag fuse back in. Put the son in the back seat.

Everyone will be much safer.

SeniorXJ

Jeep was loaded up with Jiu-Jitsu mats in the back.

Airbags wont deploy anyway with the winch bumper.

Thanks for the safety tip, now can we keep it on topic please.

djb383

Does the heater blow hot when the needle is at the 1/4 mark and the motor is at operating temp (running for a while)?

SeniorXJ

Don't know, didn't try, but will do so tomorrow when I grab a new t-stat.

djb383

U may not need a new stat. If the heater is blowing hot, when at the 1/4 mark, your gauge is lying to u. Heater performance will suck at 150 actual coolant temp.