Weird temp, gauge behaviour ?

[eeyore]

Hi -

I know something similar to this is covered in a few existing posts, but I have yet to find an answer to my particular problem in any of them, so.....

1.9 Vectra CDTi 120 (pre-facelift '05)

My temp. gauge almost NEVER moves off zero, despite the length of journey (did 100 miles last night, with it sat on 0 apart from an occasional feeble movement up to maybe 40 degrees, then back down again).

Put the BC in to Testmode last night and kept an eye on the coolant temperature reported in there... which I assume is fed by the same sensors that drive the dash gauge... and it was running at 65 - 70 degrees, occasionally up to 80, which feels on the low side of normal I guess... but certainly more than reported on the gauge (zero!).

I noticed that, at anything below 70 degrees (as reported in the BC), the dash gauge was at flat zero, but even 71 degrees (reported in BC) would move the dash gauge up a bit !. I sat in a layby and cooked it, got it up to 80 degrees (BC) - and lo and behold, the dash gauge was also reading 80 degrees !.

I started to suspect simply a faulty dash gauge.. but the air from the heater is not nearly as hot as I'd expect, either. Have checked coolant levels etc and no problems there..

Any ideas please folks ?

Cheers -

Chris.

[dh.dti]

Replace thermostat

[clairey83]

That sounds like my Astra...and it had had the thermostat removed by the guy before me. In winter we put a plastic feed bag over the front of the radiator (a la ice road truckers ha) and it lifted the temp gauge to 80 most journeys and I actually got heat out my heaters

[Big Dave]

My temp. gauge almost NEVER moves off zero

The guage doesn't start at zero though. It only registers from something like 70 deg upwards.

As suggested though, change the thermostat.

[disco dan]

Replace thermostat

same symptoms myself although a different engine. New thermo solved it.

[eeyore]

Sounds pretty definite then - thanks all ! :-)

[waky]

Aye exactly what mines was doing, sat at the bottom of the gauge (70') apart from the very occaisonal time it would creep up, changed the thermostat last night and all fixed, now sits at around 85' driving!!

I got my new thermostat from had who had it in stock, (comes with new housing and temp sender) for £45 and some new coolant at £5, took an hour to change as the hose clips as a nightmare but it's a 'simple' diy job if you're handy with the spanners

[waky]

Aye exactly what mines was doing, sat at the bottom of the gauge (70') apart from the very occaisonal time it would creep up, changed the thermostat last night and all fixed, now sits at around 85' driving!!

I got my new thermostat from had who had it in stock, (comes with new housing and temp sender) for £45 and some new coolant at £5, took an hour to change as the hose clips as a nightmare but it's a 'simple' diy job if you're handy with the spanners

[eeyore]

Cheers for that Waky :-)

[monty2000]

Everybody seems to be reporting temp gauge probs as the cold weather sets in.
I rekon its just the weather keeping the temp down.
my gauge operates normal when the weather is over 10 degrees ish.
only in the winter does it hardly move.