Aldakoopa

Both 87 4.0 Jeeps I have owned didn't have thermostats in them. I went to replace the thermostat in my old Jeep and there wasn't one, and it had been running fine so I left it out. The one I'm trying to fix currently was overheating, so I bought a new thermostat for it, but it doesn't have one either. Should I go ahead and put the thermostat in, or leave it out? I have replaced the water pump and I'm about to replace the radiator and remove the clutch fan to convert it to electric.

n_a_i_w

in my opinion yes you should. it helps the engine run at its designed temp.

djb383

Put a t-stat in.......at least a 180.......git 'er done.