sssstew wrote:
Re the OAT, theres some discussion about this on the 500 register forums and also on minifinity some time back will need to take another look, i seem to remember something about corrosion between the mixed types so a bloody good flush is needed or the system silts up.... dont quote me on that, will need to do some more reading.
There's truth in this.
ARE (link below) used to have a pile of pages dealing with the nasties in a cooling system, and a big problem was that coolants were reacting with each other and the glycols were turning to jelly. Once they deposited on hot surfaces, or were allowed to dry out they turn to calcium like deposits which insulate the water from the jacket the build up is attached to.
So the story is, buy a known coolant. Flush out the system including overflow tanks of as much coolant as you can (I like to fill/empty/refill a couple of times to dilute it down) and then refill your system. All this is avoidable if you use the same coolant each time, so I stick to a known brand like Castrol or similar. It's easy to pick the same bottle in two years time that way.
http://www.are.com.au/feat/techtalk/techtalk.htm