Hi, firstly happy new year to all, secondly... My car runs on the guage very low, only just moved the temp guage off the bottom a bit under general running, even after an hour or so. If you leave it to sit or in traffic, it will eventually run up to indicated half way on the guage, but as soon as you set of again, it drops well down.

Is this normal or is there something I need to think about? New thermostat?

Also remember, it may be a good thing as at the mo it's generally coldish here, average 15 degrees, but not long it will be in the 30s, so maybe good that it keeps generally cool?

Happy New Year to you ratty99! My Barchetta's temp gauge always read low and the cooling fan hardly cut in even on hottest days. The thermostat was diagnosed as faulty and the gauge looks much healthier now, though I think the car is still a bit over cooled. By contrast, my Uno has a gauge that reads low but the engine temperature is fine. I've put this down to an inaccurate sensor or slightly faulty gauge, either of which I can live with. Worth doing a few simple tests, such as checking temperature of inlet and outlet hoses to radiator as engine warms up to see if thermostat opens as it should.

I'll support the following:

1) a bad thermostat

2) excellent cooling

3) combination of both.

The fact that if you idle the engine with no forced radiator cooling and the temp rises till the fan cuts then in is a good sign *if* they self stabilise.

If moderate airflow over/into the front cooling radiator forces the temperature well below normal then this is a sign of a faulty thermostat.

A point of info/caution is that the Barchetta has a huge radiator with massive cooling ability. Even after fitting a new and fully functional thermostat the engine temperature guage can often read lower then normal (horizontal / 90 deg.C)

All thermostats have a bypass path not regulated by the thermostat valve. If engine demand/power is low but air flow/cooling is good then the bypass circuit can over cool the engine. This will result in the temperature gauge dropping dropping below normal values.

In addition the cabin heater circuit bypasses the thermostat (in some designs) so can add further cooling not compensated for by the thermostat.

My temp gauge always appears a tad low, which i thought was contributing to the idle valve issue, taking ages to drop the revs when car heats up.
Ive also had a minor water leak, but couldnt find the source.
As ive been tinkering in and about the thermostat, i thought it looked as if it was coming from that ??
So bought a new one €30, online and delivered today. Removed the old one and found underneath a crack in the housing between metal and plastic pipe section.
Also looked inside and the old one appears open ???
Am i correct ?
Look at the new one compared to old one!!
Glad they are still delivering parts, so i can do jobs on the car whilst in lockdown !!

Yes, thermostats normally fail open....I think you can be confident the new thermostat will cure your cool running(it did on mine) and your water leak. I've also been doing a few little jobs, think I might take the opportunity to do a full service

All the best

Mike