I just happen to notice that my 190E 2.3-16 cooling temp drops to 80 degree Celcus from the norm of 100 degree Celcus. Althought the embient temperature in New England is getting cold, but I have never notice this much changes before. Is this mean that my thermostat stuck open? or could it be something else.
This car has 180K miles and still loving it.

Alex