Boiling coolant?

[FnomnaVZ]

Are the thermo fans working now? I think they kick in around 115 deg on the VZ. Could take a while to get there - put the digital display on.

 

[Luke52]

115 degrees? Are you serious?

Jeez. I was freaking out today because they weren't kicking in. Took it over to the boys across the road from work, they had the scan tool on it, and the temp was showing at 108 degrees, and still no fan. I thought that was fairly high, and they should be turning on by then...

 

[RiCeY]

VE V6 kicks in at around 109 degrees from memory... VZ Im not sure

 

[greenacc]

Do the fans work when you switch AC on ?

 

[ozzypole]

'Put the key in the ignition, hold down the mode and set buttons, and turn your key to the "on" position. The screen will show the GM serial number or something like that. Then press the mode button to browse through the various information.' Luke52, Thanx for this helpful info.

 

[Torquative]

alright, I did have this somewhere else because I remember typing it, when we were discussing cooling fans earlier in the year ... but I cant seem to find it anywhere.

This is from the VZ bible, so please dont try to prove it wrong. I know this info will help people in the future too. Sorry for my shotty spelling, its midnight, ben a long day, this computers laggy as hell and annoying me and 'm trying to copy from pieces of paper

Conditions for Stage 1 Fan Operation

1 The Engine Cooling Fan Relay 1 is turned ON when :

- Air Conditioning request indicated (YES) and the vehicle speed is less than 30 km/h
-Air Conditoning pressure is greater then 1 500kPa (so no, it wont turn on just because the AC is on unless the pressure is above 1 500kPa)
-Coolantg temperature is greater than 104 C OR
-An engine coolant temperature sensor failure is detected by the PCM OR
-When the ignition switch is turned from ON to OFF and the engine coolant temperature sensor is above 117Cm the ECM will continue to engergise tyhe Engine Cooling Fan Relay 1 (R7) for approximately four minutes

2 The ECM switches OFF Enging Cooling Fan Relay 1 when the following conditons have been met:

-Air Conditioning request not indicated (NO) and the coolant temperature is less than 99C OR
-Air conditoning request indicated (YES) with pressure less than 1 700kPa, vehcile speed greater than 50 KMh and coolant temperature less than 99 C

Conditons for Stage 2 Fan Operation

The ECM determines when to enable the Engine Cooling Fan Relay 2 based on inputs from the ECT sensor

1 Engine Cooling Fan Relay 2 is turned ON if the Engine Cooling Fan Relay 1 has been energises for one second and the following conditions have been met:

-if there is a ECM message response fault, setting DTC P1258
-an ECT sensor failure is detected by the ECM.
-Engine coolant temperature is above 108C OR
-Air conditioning pressure is greater than 2 000kPa

2 If Stage 2 has been enabled, the ECM reverts to Stage 1 operation when:

-The Engine Coolant Temperature is less than 103C and
Air conditoning request not indicated (NO) OR
Air conditoning request indicated (YES) and the pressure is less than 1500kPA

 

[Luke52]

Thanks Torquative, that's awesome.

Greenacc, yes the fan works with the A/C. I did some experimenting last night. Pulled the coolant temp up on the dash, and let it idle. It reached 108 degrees, and sure enough, the fan kicks on. So it would seem as though everything is functioning as it should.

I just didn't expect the trigger temp for the thermos would be THAT high...

 

[coxy47]

Just thought id let you no i have just had exactly the same problem, symptoms and all, on my vz executive sedan.

Turns out the cause was that the radiator cap had failed preventing the system from being pressurised thus letting the coolant boil.

I bought a replacement cap from holden for $29, flushed (after loosing about half the coolant that should be in the system) and refilled the cooling system and it seems to have fixed the problem.

 

[FnomnaVZ]

Yeah, that quoted section is what I was trying to remember - must have been thinking 105, not 115.

 

[eruption1]

I am also having this problem with boiling in my VZ Crewman. Tried to get a thermostat and seems they only available from Holden and they want $88
That seems rather steep for a thermostat. Now after reading this discussion im wondering to i try a radiator cap first or just get the thermostat or both.