i have a 99 mark 1. temp gauge only goes about one third of way when car has warmed up. only when idling it does it go to half way and then fan kicks in and needle drops back to one third again. Heater works fine. engine performs very well. Is there a problem with the sender or the thermostat? if the engine is running cool will that do any harm?

It should always do that, between 1/4 and 1/2 is normal, over half the fan should kick in, and up to the top, time to call the AA man and look in auto-trader...

Hi,

Mines doing the same too. It started doing it last friday. I would drive about 3-4 miles and the temp gauge goes up to 3/4. It doesn't seem to be over heating and looks deffinatly to be the thermostate. It's going in the garge tomorrow to have it looked at, so i'll post back when i find out.

Donal said:

i have a 99 mark 1. temp gauge only goes about one third of way when car has warmed up. only when idling it does it go to half way and then fan kicks in and needle drops back to one third again. Heater works fine. engine performs very well. Is there a problem with the sender or the thermostat? if the engine is running cool will that do any harm?

Click to expand...

This is exactly what mine does, and mine is the same age car. temp gauge kicks in about 90 degrees or so, (it's in the hayens) and stops around 89 degrees.
Yopurs is working fine so don't worry.

yep my sisters mk1 55 temp stay at about 1/3 when warm and only goes higher when stationary then fan kicks in.

Thanks for all your replies. Looks like there is nothing to worry about. I think that the temperature sender unit may be unreliable. I have heard that if the engine overheats the sender unit can be damaged. Perhaps this happened with previous owner. Previous owner had minor front end colision so I wonder if they damaged the rad causing a leak. As result engine may have overheated damaging sender unit. Or maybe the fiat sender unit has been faulty from new.

Whats a temp gauge

My 55 aint got one

cphfiat posted the following some time ago...

"My problem is - after flushing cooling system and adding new coolant and thermostat - that the gauge tends to stay in the 8:40 position with cooling fan kicking in at 9:00.
Before change of coolant and thermostat the normal postion was 9:00 with fan kicking in at 9:50."

this is exactly the same problem as I and others have had. anyone got any idea why the fan now kicks in at a lower reading than usual?