Technical Overheating? - But don't believe it is (Grande Punto T-JET Sporting 1.4)

[everson38]

Hey all, Hope everyone has been keeping well.

I have a possibly unusual issue an hoping someone can shed some light. (I have a 1.4 Grande Punto T-JET Sporting 2009)

So last weekend i popped out in the car. I was driving for a approx 3 mins and just happened to look at the dash and saw my temperature guage in between the
90 degree mark and the red overheating mark. I immediately pulled over into a car park and shut off the vehicle. I looked in the bay and reserviour was to correct max line, aux belt was intact. I left it 15 mins to go cold and then turned it back on and it held at 90degrees as you would want but i took it back home and left it a few days. Today I came out again and turned my keys to the ignition position (electrics only position) and saw the temp needle start at approx 30degees (see picture). I then took my keys out and the needle is remaining around that 30 degree mark and is staying there, as if it thinks this is the new 0 degrees. (see pic). Bar the needles playing up, the car running perfect and you would not think it is over heating. In the winter I had my LCD screen go blank (see pic) due to cold weather / moisture, not sure if related but full picture.

What Ive had done:
New thermostat (genuine fiat) couple years back + tested it was working before installing.
New water pump (lucas brand) done by a garage a couple years back
New timing belt done by myself couple years back (genuine fiat - whoe thread on that saga)
New coolant (triple qx - done a couple years back, due a maintenance change this year)
New Aux belt and tensioner (genuine fiat) done couple years belt


Any ideas of where to start or what the issue is would be great.

Thank you.

 

[GrandePunto PL]

Are you new to the Internet, to this forum and Fiat cars (or cars in general)?
SEARCH before starting new thread! What's wrong with you people?
Plenty of existing topics about temperature gauge misbehaving.
Obviously, you have an electrical problem (not mechanical/hydraulic), 99% sure.
Check (these are absolute basics): battery (charge level), main ground ("earthing") for corrosion, wiring/connectors and fuse box (corrosion again), temperature sensor operation (via OBD2, FES or MES software), plus read error codes (if there are any). Stop using "CITY" mode for couple days (draws a lot of current).
Temp. gauge itself (or whole cluster) failure is rare, BodyComputer or ECU too, but it happens. Blank LCD is not a good sign...