Cooling system oddities

This past month i've slowly replaced almost every peice in the cooling system on my Jeep. New radiator, thermostat, water pump, and all the hoses in the system.

The most recent addition was the radiator. Before the new rad my jeep's temperature would be at or around 210*. Now the temperature never goes past 130*.

I've searched have come to the conclusion that it could either be the temperature sending unit or the gauge itself, is this correct? I'd rather not replace something that doesn't need to be.

Any help is greatly appreciated. Thanks. eace:

FYI I have a 1995 4.0L. And I use a estimated 60% coolant 40% water mixture in my cooling system. I flushed and replaced the coolant when I replaced the radiator.

Thats about the same temp mine was running when the thermostat was stuck open. A couple of times in the past decade or two, I´ve gotten failed replacement thermostats (bad out of the box). A little too much silicon, will sometimes squirt into the thermostat housing and hold the thermostat open, as will a slipped gasket.
An electronic thermometer held onto the metal part of the radiator outlet and on the outside of the thermostat housing (or the radiator inlet) will give you a fairly good idea of whats going on inside the system. Just got to hold the thermometer on there for a minute or two, takes a little while to stabilize and give you a reasonably accurate indication of the true coolant temp. Won´t be exact, but close.

That's about the same temp mine ran at for a couple days. Had to replace the thermostat. It was stuck open.


Alex

Bahhumbug, I was hoping it wouldn't be my new thermostat. Anywho, I'll replace the housing while i'm at it...

Thanks guys.