It accelerates and pulls 307 hdi

Hello, my 307 HDI 110HP accelerates when you see traveling (it goes up about 500 rpm) and in low in the city of Tironea. The Scaner does not accuse any error and the readings are all normal. unless the electrventilator is still permanent even with the cold engine.
Can anyone give me an idea what can be? thank you

Hello, how are I spent the same thing and it was the refrigerant temperaruta sensor, advice puts an original !!! the same to be safer medile for the resistance, disconnect the file and mediate the sensor that is because of the change of revolutions,
and by the electro, ahead of the radiator has a triangle -shaped box in which there are 2 relaey's fix that one of them has not been stuck is the most common in 307

Ok. I try that. thank you.