wrong mix

[samvlcal]

hi all

just talking to a mate and he said it's not good to mix two different types of coolant... he says it can turn to 'sludge'. my old man is a chemical engineer and he says that it doesn't mater, the only thing that could happen is you may dilute the ethylene glycol content, it will still protect your motor.

so whose telling the truth?

[HoZy]

Believe your dad.........

[ICUBYE]

i agree with hozy

altho I have seen a few reports that certain coolants can promote rusting and this can be worse when mixing two different coolants.

but yeah i would believe an engineer over something on a current affair or today tonight.

[pandaman]

hi all

just talking to a mate and he said it's not good to mix two different types of coolant... he says it can turn to 'sludge'. my old man is a chemical engineer and he says that it doesn't mater, the only thing that could happen is you may dilute the ethylene glycol content, it will still protect your motor.

so whose telling the truth?

Most brands are fairly safe to mix, your dad is right in that you might end up with the wrong concentration of ethylene glycol, but the main problem is that some coolants use different corrosion inhibitors which can react with each other. I've never seen a problem occur from mixing coolants though, but I wouldn't reccomend mixing that red coolant stuff with green coolant, for starters the resulting colour would be fairly disturbing. I reckon just apply some common sense and it should all be good.

[bangers]

you can't mix red and green coolant. they don't mix. they separate like water and oil. one will sit above the other. and it will do damage to the motor. you can mix different green ones together though.

[andyman]

i thought i was supposed to cause electrolosis if there is a earthing problem or a stray current etc

[vtdemon]

This sludging thing does happen and can mess with radiators and water pumps, I'm not certain about the reactions that go on, but if they cause electrolosis or cavitation take care.

Either way you should always flush the cooling system with every coolant change anyway, especially on Commodores and try and top up with the same brand/type of coolant.