VX Calais strange overheating issue

[marsh_e79]

Hi Guys,

I've had my VX Calais since Feb '08 and the whole time it's had this weird cooling system issue where randomly, the temp guage will show it to increase in temperature from normal (about half way), right up almost to the red line. I'm alerted to this by a little beeping melody that plays as a warning indicator, then I watch the temp stay up there for about 10-15 seconds before falling quite rapidly back down to normal... it might do this every half hour of 45 minutes or so on a drive across town (Melbourne). It doesn't seem related to lack of air intake from sitting in traffic either because it can happen while cruising at 60k..

Anyway, I raised the issue to my mechanic recently when he was servicing it, and he told me that it did need a cooling system flush etc.. which sounded reasonable. So anyway, that didn't help at all, infact it seems to have been more frequent since then. What stumps me is that it doesn't seem to be losing water or blowing steam out so it's not that hot, and the temp always drops back down to normal....

I'm thinking faulty temp guage/sensor/wiring?

Anybody had similar experiences?

Any input is appreciated.

Cheers.

[Hot-Rod]

Had a similar issue a while back, the Radiator on the hot side which is drivers side i think from memory can crack which causes over pressurising in radiator which causes the hot temp to come on dial. Other issues:
- Thermostat is gone, replace it $15.00 part.
- Radiator gone, replace it $180.00 part.
- Thermo fan not working correctly Unknown price never changed it.
- Make sure system is bleed after flushing, (top hose which leads into engine has a screw, turn it with flathead screw driver til all air is released from system and only coolant coming out).
- Make sure your mechanic flushes the system correctly, this means removing overflow bottle, removing knock sensors on engine, placing heater on hot and flushing system several times. Don't leave this issue as it can led to damage of the internal engine parts from lack of coolant etc especially with this hotter weather we are having.

Good luck with this all.

[dazza33]

Had the same problem, had it flushed and a new radiator. Hasn't happened since.

Cheers, Darren.

[topzone]

Hi Marsh I have exactly the same problem as you have described the only difference is that my car does it only periodically from cold after about 5 mins running but not at any other time.
I have stopped and checked the engine but it isint overheating or losing water,this led me to think I should replace the thermostat, so I did but it hasnt made a difference so tomorrow I will flush the block heater and radiator.
I want to remove the knock sensors can anyone tell me how this is done or post a link I will let you know how the flushing went.