Frozen Coolant ?

[Griffo]

Just got back from a week at Hotham. It was pretty cold -10C during the night at times. I'm glad I stuck in extra diesel treatment - there were plenty of cars having starting problems. I'm told the Alpine diesel sold at Bright is only rated to -3C, althought that could just be mountain gossip.

Anyway, crapped my pants when I got back to the Disco. Immediately obvious on getting to the truck was the coolant-red coloured stalactites of ice on the front left of the vehicle. Thoughts of split coolant lines / reservoirs or even a cracked block immediately came to mind. I searched around and couldn't find any obvious breakages so I started the car and watched carefully until I was convinced there were no leaks - made of a nervous 5 hour drive home!

So.. I thought the OAT coolant was rated to like -50C? The car is always serviced at MLR, and recently had a major, so I would have assumed they used the offical stuff.

Any thoughts on why the coolant was expelled if not for the fact that it must have frozen? I've never had it occur before

[LandyAndy]

It may not have frozen,just expanding like water does before it freezes.
Where is our Oil and coolant and chainsaw expert????
Andrew

[Tombie]

Andy has it. Just expansion..

It freezes at 50% mix at -32c

Check your coolant mix :)

[Blknight.aus]

OAT also initially freezes like a slushie mix with the water trning to ice first as small crystals until the optimal ratio is reached and the temp drops low enough to freeze the remaining mix

when the crystals form is when you start to force the coolant out as the expanding water ups the pressure.

best guess on an optimal mix is that the crystals will start to take effect at about -20 or so with the temp getting nearer to 0 the weaker your mix. a 30% mix I would guess would start to crystallize at about the -10 mark

[Griffo]

Thank you. I guess i'll have to up the mix before next trip to avoid a repeat. Much appreciated.