See my profile, Imma CJ Guy, I do not know much about your rig
I will throw out a few possibilities,
1) Is Lower Radiator Hose "Springless", Old, Squishy----Maybe it's being Sucked Flat by the Water Pump?
2) Saw this once on a rig (Stupid!). Is your belt MISROUTED, and your Water Pump turning BACKWARDS. This ran hot really fast!
3) Could it be that your Cooling Fan Clutch is Bad? (Allowing too much FREEWHEELING)
4) Even a NEW Thermostat, can be bad! Or installed incorrectly (Correct is, Spring side inside the engine, Pointy side UP) [had to include that!]
Compare the diameter of your thermostat to the diameter of a "SUBARU" stat (theirs are mostly the same thru many years, you will understand in a moment!)
On a '76-'86 CJ 258 C.I.D. (4.2 Liter) engine, the Subaru stat is a perfect fit (I run a 180 Degree, your more modern rig will probably not run correctly without the correct temperature stat as it normally runs)---195 Degrees or more?
Regardless, If you compare the "Center" (the part that normally opens in the middle of the stat, THE SUBARU HAS A LARGER HOLE, MORE JUICE (Volume) CAN TRAVEL THRU, TO THE RADIATOR TO BE COOLED!
Remember me in "Feedback", If I fix you up!
Your Turn to Talk,
Sunday, October 17th, 2010 AT 10:22 PM