VZ Cooling Problem

[bachat]

Hi guys,

Can anyone tell me what this problem with my cooling system might be.

I was in the queue for some junk the other day and noticed my VZ started overheating. It went from the 1/4 temp mark to about half way but soon as I started driving it cooled back down. Ever since then the car sits at a slightly higher mark than before when moving (like a couple of mm), and when im sitting idle in a queue or bad traffic it starts to overheat again. Maybe i've never been idle long enough but it never seems to go above about half way.

Ive checked my coolant and that seems ok, my fans still kick in. Could it be a thermostat problem? Water pump? Any ideas?? There did appear to be some brown gunk (not much) could this mean the head gasket?

Any help would be much appreciated.

[Phillshz]

VZ`s had a temp gauge faults when the cars were new(sounds like your prob),everyone was swapping thermostats and getting nowhere(it`s a major pain to change a VZ thermostat). The gauge fault lies in the cluster software,a re-flash with updated software from holden is where i would start if coolant,fans,rad cap,water pump condition etc (the basic stuff) seem ok

[ben_quadinaro]

Beleive it or not, I had a similar drama and the Radiator Cap was the problem because it was not releasing the pressure of the hot water..
Check that out also..


Ben

[bachat]

I read other posts about the radiator cap so went and bought a CRC? one from Supercheap but the problem still exists. She's due for a service soon so I'll see what they say when they check the cooling system.

If it is a temp guage fault how much am I looking at to get a reflash done at Holden?

[BRAWT_4TH]

mate im having the exact same drama with my ss ute came on to find answers maybe i might head down to holden see what THEY THINK IT IS and see how much they wanna ripp me off

[Torquative]

the alloytecs are prone to a few issues which are documented well throughout the forum

- radiator cap
- water pump
- thermostat

and the one I had a few weeks ago was an air lock causing it to overheat!

came on to find answers maybe i might head down to holden see what THEY THINK IT IS

As I said, as far as Alloytec goes theres a massive resource right here with a common theme. Below is just a sample of page 1 of 10 + pages when I typed "VZ Overheat" into the JC search bar.

V8 Im not too sure about, Ive never had one and never had to research one for overheating issues.

VZ overheating problem
Overheating Issue - Coolant reserve leak?
VZ Overheating Mystery
Overheating?
VZ Overheating!
VZ V6 190kw overheats and cant get radiator cap off [ WL statesman actually ]
VZ 2005 Executive Overheating


Hope this helps

[exastra]

Hey all,
I too had overheating issues with my VZ. replaced rad cap and fixed leaking water pump (as it went soon after a flush). This fixed the problem for ages and then it came back again. I noticed that the hose going to the overflow bottle had a split near the radiator cap. Fixed that and all good again. Something I have learned with these cars is that the overflow bottle is really important - Engine warms up and pressure builds in cooling system, cap opend and lets water out into the overflow - Engine cools down and sucks water back into the cooling system from the overflow bottle. If there is a problem ie split hose to overflow or similar (or if there is a slight leak high up on the radiator somewhere) then the system will suck air instead of water when it cools down. Make sure when the engine is cool tha the water level is full to the top of the rad cap otherwise the system is sucking air for some reason and this leads to overheating especially when sitting idling.

[KrisHolden]

VZ`s had a temp gauge faults when the cars were new(sounds like your prob),everyone was swapping thermostats and getting nowhere(it`s a major pain to change a VZ thermostat). The gauge fault lies in the cluster software,a re-flash with updated software from holden is where i would start if coolant,fans,rad cap,water pump condition etc (the basic stuff) seem ok

I am once again having such an issue.
KMart Auto cannot find any probs and have already re-bled the system. No leaks etc. I am about to change the thermostat and re-bleed but other posts have already tried this with no positive result.

I have never heard of this thing about the reflash and am curious... has anybody else heard this?

cheers!