Spiking Temperature Gauge

[HamaTime™]

Sorry to have to keep bringing this up. But my VS is very temperamental when it comes to it's temperature. It usually runs at a normal temperature of between 1/4 and halfway. Then randomly, either when I'm sitting in traffic, and even when I'm cruising along at 60 - 70 - 80 k's an hour, either accelerating or not, it sometimes spikes to 3/4, sometimes above! It does it almost every trip I make now. But just as randomly as it spikes, it just as quickly dies down to normal level, i.e. 1/4 - half

Thermostat Going?

Temperature gauge going?

Or is the engine really, just spiking in temperature randomly?

IS THIS NORMAL BECAUSE IT'S FREAKING ME OUT AND IS VERY DISCONCERTING

[WhiteVS]

mine does pretty much the same man, has been doing it for quite a while now aswell.
ill prob be doing a full coolant flush within the week and also replacing the thermostat.
ill let you know how it goes after that.

[hako]

If you reckon the cooling system is OK I'd be carefully checking the connector where it joins the temperature sensor - from memory it's the front one - the other temp sensor is for the ECU....but check the wiring on both for luck as it's not unheard of for the connector and/or cable to break or be loose.
Not sure but I think if the connector is disconnected the gauge goes straight to hot so an dodgy connection could give this problem.

[ryan1980]

perhaps theres air in the coolant, and it needs to be bled. When the sensor hits an air pocket it spikes?

[HamaTime™]

perhaps theres air in the coolant, and it needs to be bled. When the sensor hits an air pocket it spikes?

Yeah it just randomly goes up, then goes down.

I need to bleed my heater valve again. Would that have anything to do with this?

[greenfoam]

This allways use to happen to my old V6 when it had a bit of air in it, just needed a bit more water and all good

[hako]

I'm no expert but if there are air bubbles circulating in the coolant they will be exactly the same temperature as the coolant...no hotter or cooler.
Check the connections to the sensor first.

[RK5TAR]

Mine does this! It used to sit on 1/4 all the time. Over time its gone to 1/2 and now 3/4 and back to 1/2. It gets to half within 5 minutes of driving around my suburb. Whereas it didnt before. I also have to every couple of weeks top up the overflow bottle.
Im getting the motor looked at and serviced etc in July sometime when I have funds, but being a single mum with 4 kids I dont want to be out on the freeway and it overheats. I do have RACV roadside assistance but would like it not to get to the point of complete breakdown to find the problem.
RACV can do nothing unless it does overheat etc.
Butthey werent that reliable with my last car, had no idea even though I kept saying "head gasket" they nor the mechanic would listen. A couple of breakdowns/tows & thermostats etc later, sure enough it WAS the headgasket!!

[HoldenOnn]

My VS which I just sold 2 weeks ago after owning for 3 years was doing the same thing when i first purchased. I did a complete flush, then installed a new genuine thermostat and new genuine holden coolant and radiator cap and water pump tablets then filled and bled.

After this, the temp gauge settled perfect and sat between 1/4 and 1/2 mark. But then after a couple months it started to go up to 3/4 mark after first start of the day (when thermostat 1st opened once warm). I bled the system again but it seemed that it didn't need it.

I then didn't worry as the factory gauge is only a guide. I didn't touch the cooling system again for 3 year and it was perfectly running. The gauge was spasmodic and random at times and would go up to 3/4 mark then thermostat open and fly back down to normal for the rest of the day.

Don't worry too much if you have done all the new coolant, cap, thermostat, water pump tablets etc.

The factory gauge is only an indication and what is to say that the 3/4 mark is only 3 or 4 degrees hotter than the 1/2 mark. Its impossible to say unless you have someone with a tech 2 holden computer which is exactly what my best mate has at his auto electricians. The factory gauge is a guide. If you have done the full service route, then get someone eg holden to put computer on it and they will tell you the exact temp off the computer.

Regards
Matt

[HamaTime™]

All fixed, a leak in the water hose from resevoir to Radiator, flushed the cooling system and refilled it with coolant.

We are good.