indicator of the tempratur under all conditions in summer and winter , but now days the temprature pointer goes up above the middle for 10 secounds or 20 secounds then it return again to the middle .. thats not normal ,it should be in the middle for all the times , ichecked all the cooling circuit component s, icleaned the radiator , removed the radiator thermostat , fan is ok , pipes are ok ,,no leakage of water ( i donot use the cooling liquid red or green ), and the pointer of the temprature still goes up then to the miiddle !!! during driving ,,, is it the fan works late ???? or the sensor of the temp . indicator corrupted ????