I have a1994 Aerostar with the V6 3.0L motor. My engine temp is very unstable, running between 205 and 235 with an NEW 180 degree thermostat installed.
I have replaced in last several years, all hoses, water pump, radiator, thermostat several times, the fan clutch. Sometimes I see a swing from 150 degrees to 250 degrees in just a few seconds.
And not, I am not using the installed gauge, I have a mechanical temperature sensor installed.
And ideas?
ANYTHING AT ALL?