Weird overheating - VX Commodore

[keithy111]

Three days in a row now, Ive driven my 2.5km to work, on a 24 degree day(not too hot at all), and my temp gauge is going crazy. Usually she sit on under half on a drive to work, however lately shes been crawling up to above half with digital temp reading 110 degrees. I popped the bonnet this morning after the drive to work and there was smoke (or steam) coming from the top radiator hose near the radiator, and making a hissing sound , highly unusal of me commy to behave this way.

Ive flushed the coolant once, put through some stop leak a couple of months ago, got a new radiator cap, a new thermostat. However im putting only premixed coolant into her instead of a mix of water and alrdymixed coolant, as i learnt coolant alrdy had water mixed in it (i doubt this is the issue though)..

I havent bled the system yet however, would this be the issue?

 

[accentstencil]

Bleeding is very important on the V6, you will have overheating issues if you don't bleed it.
Premixed coolant should be used straight, concentrate requires 50% water.

 

[NeddyBear]

Is the radiator original, how about all the heater and coolant hoses, the heater trap and the water pump.
Maybe shes trying to tell you something.

 

[devilly]

i would be checking the top hose for a possible crack,or ring clamp loose.i agree with bleeding the system,then check the hoses top and bottom temp.and also before you start it feel the hoses via squeezing them.then start it for a min and check when you squeeze them if they are firm.this gives some idea to the pressure going through the system,and the temperature for possible blockage.

 

[keithy111]

How do you bleed the cooling system?

 

[Dayvo]

There is a bleed nipple on the top of the thermostat housing . Run your motor up to normal operating temperature and undo the bleed nipple which will let the air escape. Then do it up , run it for a couple more minutes then repeat till you get a constant stream of coolant coming out without any airbubbles. Then when the motor cools top up with coolant . Also check the level in the overflow bottle .

 

[keithy111]

Coolant coming out of the nipple?

 

[devilly]

just use big pliers and unscrew the top a little bit. here's a link that shows the thermostat housing http://www.ebay.com.au/itm/HOLDEN-THERMOSTAT-HOUSING-COMMODORE-VS-VT-VX-VY-GENUINE-/150566746782

don't use a flat head screw driver it seems to wreck them.you want a good steady stream of coolant with no air breaks in it,is the goal.i found if you cant get a good steady stream then you have a hose clamp that needs tightening.

 

[keithy111]

Thanks Fellas, I Bled it today, however bubbles just kept coming out, so i just gave it 15mins of just bubbling out of bleed screw (cause too much coolant was pouring out). This fixed the issue however, my coomy is no longer over heating for now (touch wood)
THANKS again guyss!

 

[elless1]

More than likely the plastic radiator tank has cracked under the hose,usually
where the brackets are, to mount the fan.

Before any more damage is done, id be flushing the stop leak **** out if it isnt
too late and overhauling the system. Radiators for these are cheap.

All of the stop leak products out there are more damaging than fixing. If its
leaking or overheating,somethings wrong.