What temp does your 4.0 run at?

Mind sharing the conditions when you hit those temps? Along with truck setup? I’m sure it will help someone down the line keep track of their 4.0’s health

 

In the middle when the truck is at operating temp. Don’t have a fancy scan gauge but stays there if I’m wheeling or stop n go traffic.

 

The high reading was due to my electric fan motor going bad, so it was an anomaly situation. I normally run 185-195.

 

And your truck setup?

 

Napa offers the 170* thermostat, does it require an adaptor like the urd one too?

 

Mine runs anywhere from 177 (downhill, no load) to 205 (towing uphill). Around town, 185-190.

 

Another hot one stop and go. AC off.

 

I feel like I run cold, between 80°C-85°C(176°F-185°F) Winter-Summer on the highway no load.

 

Old thread but that's normal temp for a 4.0, I believe they run a 180 degree thermostat just like the old school vehicles did.
Mine has always been in that range since it was new, it sometimes hits 190-195 on a hot day at highway speed.

 

186f

 

Well it's an old thread but i will post there since i didin't saw many post about the 4.0 (vs the 3.4).

Last year i did a full refresh of the liquid on the truck (coolant, transmission, brake, ps). Since i had the thermostat removed, i installed a new one (Gate). I didn't pay attention to the coolant temp since the needle was still at the same position in the cluster dash. Since then i bought and Ultragauge my temperature was around 200-205f (93c-96c).

3 week ago my friend did a flush and he put the OEM thermostat. I saw the temp moving from 180-190f (83c-86c) i found that odd and started to search why the temp between the truck was different like that.

Well the jiggle pin on the gate was a 3 o'clock, it seem that if it's not at the 12 o'clock position there a few degree more before the thermostat open. My temp are like everyone else now.

Check your jiggle pin !!! it make a difference.

 

184 around town in the fall winter spring. 195 summer time. Will break 200 uphill with some load. A bit higher if it's hot.

 

194-96° "normal" driving. Can hit just over 200° for short periods in the steepest mountains. I think stop and go traffic is the worst.