DEX-COOL or not for L77

[greenacc]

Yes drain the radiator, fill it with demineralised water, drive car, let it cool of , drain the radiator again after it cools, fill it again, go a drive come back let it cool, drain the radiator again, fill it with demineralised water do it for the second time I use the Air con on heat too, drain it again, fill it with demineralised water come back drain again... Now I say it will take me all day to do this.

This is a good method, Just be careful not to go driving with a big air lock in the system if you don't bleed the air out each time you fill it with water. You might find the temperature gauge suddenly shoots up to hot if that happens.
Happened to me once twenty something years ago. Had to pull over and ask a nice lady for some water...

 

[Ron Burgundy]

Yes drain the radiator, fill it with demineralised water, drive car, let it cool of , drain the radiator again after it cools, fill it again, go a drive come back let it cool, drain the radiator again, fill it with demineralised water do it for the second time I use the Air con on heat too, drain it again, fill it with demineralised water come back drain again after it cools and finished with 5.5 ltr or what is 50% capacity of coolant then top up with demineralised water + make sure the overflow container is the same. 50/50. Now I say it will take me all day to do this.

I did this on my old sv6. Did it over couple days over the weekend. Drained it 4 times and then 5th time filled it with clean water and 5L of dexcool concentrate. Also flushed overflow tank and filled with coolant as it holds couple litres...

 

[Ron Burgundy]

Good info here https://forums.justcommodores.com.au/threads/ve-ss-v8-coolant-flush-how-to.225912/

 

[mpower]

a more thorough writeup here - LS1 but the basics carry over.

DIY cooling sytem flush

Here is a DIY LS1 engine coolant flush. You need to do a complete flush when your coolant is old or when you want to switch to the green stuff. Draining the radiator and putting green stuff in is the incorrect way and it will cause problems in the future. You can't mix green stuff with Dexcool...

www.ls1.com

 

[losh1971]

I don't stress out too much about the ratio in the overflow tank it sucks down and refills each time the engine cools get cold and hot again anyway. 20 or so nights and it should be pretty well the same ratio as what's in the rad. Personally I think filling and dumping the coolant 4 or 5 times can still leave traces of old coolant.
Hardest way but best way, is to remove the thermostat, and with the hose and an adaptor plugged into a heater hose run the engine and turn on the tap while the engine is cold. Then drain it best you can and fill with coolant and water. Prick of a job on a VZ - VF I could imagine and probably worse on a V8 but at least all the old coolant is removed.

 

[VFSV6FORME]

This is a good method, Just be careful not to go driving with a big air lock in the system if you don't bleed the air out each time you fill it with water. You might find the temperature gauge suddenly shoots up to hot if that happens.
Happened to me once twenty something years ago. Had to pull over and ask a nice lady for some water...

Take note of this

I see the radiator drain plug is a Allen key. When you loosen it does the plug fall out or stay they or have a attachment to keep it there or other so you dont lose it on the tray below.

 

[VFSV6FORME]

Had a quick look at the WN Caprice with a L77 engine in it and I see a Full try underneath, I see a hole, look up the hole, I see a plastic Allen screw about 60 MM up (could be more and less) Have to see if I got a Allen set to remove this as if its to high my ones might not be long enough even if I try the key the other way around.

 

[greenacc]

The plug in the V6 radiator has legs on it that stop it from falling out when it's unscrewed. Don't overtighten it as they can crack when they get old. A set of 3/8 drive Allen key sockets is a great investment, then you can connect them to a long extension bar and reach fasteners from 40cm away

 

[Immortality]

I haven't run coolant in years as it reduces the efficiency of the cooling system even though it increases the boiling point (only marginally). I use tap water with Penrite 10 Tenths Race Coolant Inhibitor. It never freezes were we live (but does get very close) and never had an issue.

Yes tap water can have minerals, and I like the point about the kettle and the built up minerals from tap water. How much water does the radiator hold and how much tap water do you think goes through your kettle in a year to achieve the buildup? Your kettle will see hundreds of liters of water, your radiator might see 6 litres of water + coolant concentrate every couple of years.

 

[stooge]

Your kettle will see hundreds of liters of water, your radiator might see 6 litres of water + coolant concentrate every couple of years.

because it is a closed system 6 or 600 liters does not matter because the concentration of minerals for every 6 liters is the same and the majority of the minerals remain inside the closed system.
if it was an open air system one could theorize that over time you could boil off some of the minerals but it is not an open air system and it does not get to a boiling point for a substantial amount evaporation to occur.
electrolysis caused by different metals within the system is another factor at play which is amplified by the salinity of the water used.