Hi,
Have an odd fault, when the temp rises fast, the faan kicks in and temp drops fast to medium temp in 1-2 sekonds. I have changed the cooling temp sensor and the symptoms are the same. Temp is realy unsteade.

What shall I look for?

/m

thermostat or header tank pressure cap... my money is on thermostat!

thermostat is new, 4 month old.

fiat original parts or aftermarket parts?

Orginal?
http://catalog.meca.se/ProductSheet.aspx?Article_ID=2477010&CarReference_ID=4022&CategoryType_ID=1

tank pressure cap? so easy, i will check that. I is always pressure when I open it.

cap is ok. I will check petrol pump/filter.

menola said:

cap is ok. I will check petrol pump/filter.

Click to expand...

When you tested the cap, what pressure did it release at?

Unlikely to be petrol pump or filter.

Hi,
I have no testinstrument for testing coolant fluid cap. When faan kicks in, temp reading goes up. Why? Strange.

/menola

Hi,
Please, do someone have more ideas? Please help me.
Regards menola

If you have the 1.6 then 99% a faulty ECU. A lot of people in the greek forum have faced the same problem and it prooved to be a problem with the ECU (me included). Probably has something to do with ECU being on the top of the engine and getting HOT!
The fan kicks in because the ECU believes that the temp has risen for real...