koujyr

I have a problem with the temperature gauge being stuck in the position at the time when I start up the car. When I do it the first time in the morning, it would not move and stay on 'cold' until I completely shut the car off and start it up again.
So, I let the car work for a couple of minutes before driving, shut it off, start up and see the gauge move to 1/4 and stay there. After driving the car for a couple of miles, I would do the same thing and see the gauge move to almost 1/2. If I do not do that, the car would overheat spewing the coolant from the radiator.
I bought this car from someone so I can not say when the problem started.
I did check that the fan turns on, although I do not see any gauge movement.
I did replaced the ECT sensor (no change in behavior).
I'd appreciate an advice on how to diagnose the problem.