Re: Temperature gauge EF I6
What you need to do is take your radiator to a good radiator specialist and get it thoroughly cleaned. Do not use any of those coolant additives because they do **** all. The radiator core needs to be professionally cleaned and serviced. If you don't mind paying over $200, get yourself a new radiator.
After that, buy a new thermostat especially if it's never been changed before or at least not for a while. Get a good quality coolant (don't be a tightarse in this area) because a good coolant makes a big difference.
In the end make sure you bleed the air from the cooling system properly.
This should take care of your problem.