Hi all.
I boiled the sensor and here is the results, numbers inside ( ) is the value it should be:
20 degree C : 2280 Ohm (2500)
40 : 1760 (1200)
50 : 1330
60 : 1050 (600)
70 : 813
80 : 930 (350)
90 : 1114
100 : 790 (175)
So, looks like I have a broken engine cooling temperature sensor.
Well cooked Mr Magoo, I think a visit to shops for a new sensor is required.