Fiat Doblo 1.9 65cv Heateramineto problems ..

The problem is K raises the temperature Asta 90º very difficult after a lot of time to be underway then it lowers me to 50º and no longer saube to 90º and it was kept in 50º or even low to 0º Algen can help me ?? Can it be the thermostat or temperature sensor ??? Thank you.

In the radiator you have a thermocontact that when it reaches 90 jumps the fan, guide for that and if the indicator needle does strange things go to the body of the thermostat near the right side of the Cuatatahay block you will have the thermorestore the clabija and it puts direct negative (I think it goes like it) and the needle reveals to move. There are seeing whether thermorers or the indicator is broken.

Check the thermostat, you can be locked open and so you will never have an optimal temperature, tell us how you go, greetings.