VT commodore temp rises then lowers ???

[JakeysVT]

when driving the temp rise quite high the other day then it lowered agen but while idling it went right back up agen ? i have tested the thermostat, and drained the cooling system and put fresh water and coolant in it i have also bled the system too so there is no air in it

any help will be much appreciated

 

[FC50]

I have exactly the same problem with mine, even after a brand new radiator was fitted recently, so new thermostat and cap.
I can put my hands over the motor while it peaks at max temp and it doesn't feel hot or smell.
Drives me mad, real "Boy who cried wolf" stuff.

another thread here with same issues.
http://forums.justcommodores.com.au...-commodore-temp-rises-then-lowers-wildly.html

 

[Dayvo]

If you don't bleed the cooling system you can get a faulty reading on the temp gauge . It will read hot but the temp is normal . Run the motor for 5 to 10 minutes to pressurise the system then undo the bleed screw ontop of the thermostat housing until the air stops coming out and you have a constant stream of coolant . You will have to take the engine cover off to do it .