VZ Cooling System Thermo Fans

[IJ.]

If the coolant is low enough that it's below the Sensor the Engine is dead....

[super coach]

Checked this morning no coolant registering on the dipstick at all undid the cap and there was full of coolant. Will give it a go at bleeding the system and see what happens.

I checked what my V2 Monaro temp runs at and its between 88-90 the VZ is a little higher which is in the range of the fans hence why they keep coming on all the time

[IJ.]

Checked this morning no coolant registering on the dipstick at all undid the cap and there was full of coolant. Will give it a go at bleeding the system and see what happens.

I checked what my V2 Monaro temp runs at and its between 88-90 the VZ is a little higher which is in the range of the fans hence why they keep coming on all the time

Just fill the Reservoir, it's doing it's job if the Radiator is full, eventually it'll bleed all of the air out, The coolant that's missing from the reservoir is now replacing air in the engine....

My VZ will run at 100 ish in traffic, no cause for concern.

[super coach]

So just top it up & not worry? How will it bleed itself? Should I still run the heater when driving it?

[white lie]

The radiator cap is the highest point in the system, air will rise in water and end up at the cap. As long as the cap is off, it can't pressurise so the air can escape. Watch it while it's warming up and see if you can see any air bubbles at the cap. If you can, then there was air in the system

[IJ.]

So just top it up & not worry? How will it bleed itself? Should I still run the heater when driving it?

The radiator cap is the highest point in the system, air will rise in water and end up at the cap. As long as the cap is off, it can't pressurise so the air can escape. Watch it while it's warming up and see if you can see any air bubbles at the cap. If you can, then there was air in the system

As White mentioned the Cap is the Highest point, as the engine heats up any air in the system eventually ends up there and the coolant expands forcing the air and some coolant into the tank, as the motor cools the coolant contracts causing a partial vacuum and sucks the coolant from the bottom of the tank back into the radiator keeping it full and free of air.

The Heater tap never closes 100% so this action covers it as well, the bleeding procedure is more for the first fill of a near empty system, I've found the VZ is pretty good in this regard, 5 minutes of idling cap off usually does the trick then just add to the tank as needed.

[bozodos]

I just replaced the radiator in my VZ (while changing the cam sensor) and idled it with the heater on for the 2 minutes or so before it would cut out of its own accord, only needed to do that twice and the radiator was full. I also squeezed on the hoses etc when the engine was off.

[super coach]

So I just topped up the reservoir went for a drive fans came on, checked all pipes & they were all hot including the one that runs to thermostat. So that makes me happy knowing coolant is moving around.

The next question I have is what is the standard holden setting temp for when the fans should come on? As I have had a tune & am thinking maybe he changed them to come on abit earlier than normal!

[white lie]

VZ may be slightly different but my reference says
Low speed on - 98, off - 95
High speed on - 108, off - 102

AC on/off, AC system pressure and road speed also has an effect on them.

Don't think i'd like waiting to 108 degrees before they kick in to high gear!

[Micks]

So I just topped up the reservoir went for a drive fans came on, checked all pipes & they were all hot including the one that runs to thermostat. So that makes me happy knowing coolant is moving around.

The next question I have is what is the standard holden setting temp for when the fans should come on? As I have had a tune & am thinking maybe he changed them to come on abit earlier than normal!

I wouldn't be getting excited about fan hi/lo on/off settings as this will only come into play when the Vehicle is slow moving or idling! The cut of the fans self propel @ speed & generally the air passing over Rad. keeps the engine cool.