Overheated ZX - any ideas?

[ChristoT]

[quote author=ChristoT link=topic=11515.msg124122#msg124122 date=1391093919]
[quote author=darrsi link=topic=11515.msg124121#msg124121 date=1391093557]
Did you put the coolant in yourself, or was it there from the previous owner?
If there was more water than coolant then the fluid would boil like kettle water, as coolant/antifreeze raises the boiling point, as well as lowering the freezing point.

Previous owner.

All I did was clean some of the gunk out of the header and top it up with distilled water.
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So there is always the chance that the previous owner has been topping up with just water as well.
I think you really need to get rid of the old fluid, and probably best to do a Radflush as well, then refill with the proper mix just so you know for sure what's in there.


And as Gnasher says, what gunk are you on about?
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First I need to strip the engine to check for damage. So it will be getting  full clean anyway.

I have no idea as to what the gunk actually was (it smelt pretty foul!) I suspect it was old coolant which had mostly evaporated, leaving the stuff in the coolant as a concentrate in the system. It didn't flow that well, and obstinately sank.