great question
the ECT is just the engine coolant temp sensor the ECU uses it to stage up from cold running, warm then hot, its a key sensor.
the stock EPA thermostat is rated at 180F, so that is the correct temperature hot, it regulates at the stamped on its side, temperature but can be 192, or 195f.
coolant temps can be wrong, for many reasons, (for sure in alaska. or when real cold out)
thermostat bad , missing, upside-down , bleed hole not up hill trapping air under it,, wrong thermstat (marked say 160f) , or the rubber ring missing allowing it to float about.
or clutch fan seized.
this is covered here,
http://www.fixkick.com/Cooling-engine/Fr...r-cab.html
from the point of view of heater core weak.
the 1.8l has more bad tricks.
the ECT is just the engine coolant temp sensor the ECU uses it to stage up from cold running, warm then hot, its a key sensor.
the stock EPA thermostat is rated at 180F, so that is the correct temperature hot, it regulates at the stamped on its side, temperature but can be 192, or 195f.
coolant temps can be wrong, for many reasons, (for sure in alaska. or when real cold out)
thermostat bad , missing, upside-down , bleed hole not up hill trapping air under it,, wrong thermstat (marked say 160f) , or the rubber ring missing allowing it to float about.
or clutch fan seized.
this is covered here,
http://www.fixkick.com/Cooling-engine/Fr...r-cab.html
from the point of view of heater core weak.
the 1.8l has more bad tricks.
http://www.fixkick.com