VW GACEL 88 Temperature problem

My 88 Volkswagen Gacel heats me, I go on a route and I have to go to 80 km/hour no more than that because at this speed the temperature is already limited and always with the fan ignition in manual if I pass that speed the temperature reaches the top and I do not know what can happen, what should I do since the electro works the temperature marker also, what can I do?

The most possible that the thermostat blocked a simple way to see if it is to touch the two hoses that leave the radiator if they are equally hot both means that the thermostat is possibly fine if they have dirgent temperatures the thermostat is blocked, it can also be the water pump, you have always used the additive for radiators or only use water checks and make me know how to know

Good apologize if the subject dives, but I see that many people have temperature problems, and there are thousands of questions, if each one says the tips of things that happen that they are not logical and we review the refrigeration failures we can kill all the birds of a single shot:
I have a Seat Cordoba, 97, 1.4, the temperature does not low from half System, I put refrigerant, the thermostat opens, the good sleeves, I did not measure the pressure of the pump, but when the output rubber pulls tightly, the strap of the times is good, if I go on the highway, the temperature should lower and it comes to do it sometimes, go down this low time and climb up again, in cases so what is done? The engine has 120mil km, it has no strength problems or anything like that, in cases so I don't know what to think !!

Look, it's about the thermostat changed it, for an original preferably so that it does not warm up anymore [ /size] there are people who will tell you that you no longer put it but it would be an error.

To that crowstro there is a string of something that you see to see to know what is happening, see first if you have the tartar radiator clean, if you do not have any leak, when it war Heat and there it is seen if the failure continues, also fix if the water runs freely removing the plug when it is cold and turned on, there is any water return line also the fan can be invested and if it does not check the time and also the escape manager since that happened to a friend that all the heating was the escape man Bye
PD puts the radiator plug after the test that you don't forget.