Temp gauge takes ages to get to 90 only on idle. it fe

[jingerman]

Vectra C 1.9cdti 120 05 Plate.

Due to low mileage daily the car doesn't get time to heat up.

So today I decided to drive for 40min and no joy stayed on 0.

Eventually parked up and left on idle and it started to climb and it went to 92 approx and back to 90.

My issue is when I put fan on it decreased in temp and more worryingly when I drove off, it fell to 0.

Even though I drive 10 miles I get warm air, that's with me changing gear at 2k on all gears.

Is the above normal behaviour? Or is the recent cold weather cooling the temp down to 0 or is it my fuel saving low gear change the culprit?

Many Thanks

[justin32]

if you hold the setting button down on the head unit until it bleeps and then press the BC button you will scroll though some info, one of them will be the coolant temp. The gauge wont start to move until it hits 70 degrees which in a diesel can take a while.

Today its been freezing and I did the school run and dropped the misses off to work which took just under an hour. My gauge never moved but I was in slow moving traffic and lots of stop, starting. If I go on a run when it cold without stopping it takes about 15 mins.

If its falling to 0 then I could well be a faulty stat which is very common on these cars.

[Dog_Book]

Lordy

[fatfred]

Lordy

Moderate!

[Big Dave]

Thermostat needs changing. It's stuck open by the sounds of it.

[jingerman]

Its not causing me any driving issues, can I just continue using the car? it does raise up to 92ish and returns to 90 when idle. Only drops to 0 when driving or fan on.

I get heat through fans as normal.

I only drive 4 miles a day.

[bonehead]

I'd go buy a petrol, probably be more economical!

it does sound like the 'stat is stuck open.

[justin32]

I think 86 degrees is the correct running temp for a diesel, mine only ever hits 90 or above in the summer when im stuck in traffic.

It does sound like your thermostat is at fault.

[fatfred]

stat stuck. Make sure it's oem to be sure you're not doing it again. And no it probably won't do the car any damage except maybe dpf if it's an auto.

[Dog_Book]

stat stuck. Make sure it's oem to be sure you're not doing it again. And no it probably won't do the car any damage except maybe dpf if it's an auto.

How do you know these things