coolant replacement

[89 jas]

when replaceing the coolant from empty in are gen 3 should i used just concertae or readymix or the mixure of the both or half concertae & half deminerlize water or what the best for it thanks for any help

[Drewie]

If it going in a GENIII I would stick with the factory RED coolant (Dexcool) as it was designed for the alloy engine. That's what they came with from the factory and it has a 5 year life.
I think it is some form of organic coolant especially designed by GM for the alloy motors. If you go for some aftermarket brand I would make sure it is the RED stuff and suitable for the GENIII, I realise others may run the GREEN coolant but I personally would stick with what the GM engineers designed the motor to run with. My VX SS has had the RED GM Dexcool in it for the past 9 years, it has been changed once at the 5 year mark.

[wortus]

If your flushing the system you need to add the concentrate first, the correct amount and then top up with water. Reason is unless you drained the block there will still be water in the block and if you add pre mix it will get diluted. For example in a V6 flush with clean water then make sure you remove at least 6 litres and then add the concentrate and top off with clean water that way it's 50/50.
I'd also stick with the coolant recommended which is the red stuff, give the Nulon brand a try their green stuff is better than the GM product so the red may also be better.

[2DIE]

I would use what is recommended, my friend had a VT V6 and was using the wrong coolant and it corroded the inside of the motor (possibly just welsh plugs I dont remember) and it was expensive for her to get fixed.

Even though its not the same motor something similar could happen if you just used cheap stuff.