Another cooling question...any ideas?

I have a 1960 cj5 with an f134. It has a new three core radiator. I have done some searching and I know the coolant gauge isn't that accurate. But here is whats going on...I drive it around on the weekends and the temp stays just about mid way on the gauge. I checked the coolant temp with a meat thermo and it read about 180. Now..here's where I am confused. I drive it into work. about ten miles with an outside temp close to 80 degrees. Gauge reads the same, just over mid way. When I drive home at midnight, with an outside temp closer to 55 or 60 degrees, the gauge just about pegs all the way hot. I can even smell coolant. Didn't have my meat thermo with me so I haven't verified the temp, but why would it run hotter like this? I would think it would hang close to the thermostat temp even more than in the warmer temps.

 

if your low on coolant, the motor will run hotter. One of the better mods i did on mine was to add an overflow jug to the rad. otherwise, the collant expands and dumps out of the system, leaving you low.

another thought is to get one of those fancy rad caps with a temp gauge built in and see what the temps really is.

 

Is going to work (downhill) and coming home (uphill). Putting more of a strain on engine (hurry to get home)? Are you having to top off radiator after each trip? Do you find puddling under rig after a trip? Is your fan belt tight? Is your temp gauge mechanical or electrical?

 

Sticky thermostat?

 

whenever i change a thermostat out i get one that when it goes to crap it stays open instead of closed.