Jeep seems to be running below operating temp in cold weather

rebelles

TJ Enthusiast
Joined
Feb 7, 2022
Messages
113
Location
MS
On the 01 TJ (4.0/5-speed) I have that I took to my camp, I noticed that this weekend it seemed to take a long time to come up to close to operating temp and really didn’t seem like it was running as warm as it typically would (maybe around 200 on the gauge). It seems like the thermostat is stuck open. I know that when it was warmer, it didn’t take too long to go up to about 210 on the gauge and then settle in just below that (like thermostat opened correctly).

It has been pretty cool weather for the south this time of year, mid/upper 20’s at daylight rising up to mid/upper 40s during the day. I know the Jeep has a recently installed 195 degree, non-safety thermostat with the correct Mopar coolant mix. Any people that operate at TJs experience similar thing in cold weather?
 
It depends on the T-stat installed. Some are more accurate than others.
For what it's worth , when I have had a T-stat hang open you would be lucky to get the temp up to 140 -160 degrees.
200 degrees is not that bad , if the temp is really 200 degrees.
Remember the T-stat keeps the temp at 195 degrees minimum.
 
It’s definitely running cooler than it was a few weeks ago when it’s fully warmed up and taking a lot longer to get to that temperature than a few weeks ago.
 
Perhaps a store brand thermostat was installed and it failed prematurely, replace it with a Mopar or Stant.

Yes, it’s a store brand. I installed it. Got caught on a Sunday and needed to change it after the previous thermo (which was a safety thermo that I didn’t install) had locked open. I guess we will see.