Dont kinow about the color .

The pebbles and sand are calcium carbonate that 'precipitate' out of
the water when it touches the hot engine metal. Use distilled or
demineralized water to prevent this. Doesnt matter what color the
antifreeze is, if the water get super hot - out come the carbonates!
..... called boiler scale!


In article , santacruz
wrote:

I don't know how color relates to chemicals - but a friend recently
bought a sailboat - turned out it had cooling problems that the test
runs didn't point out. It had green antifreeze in it. A lady capt down
the dock said you should only put orange antifreeze in marine diesels
otherwise they develop cooling problems from some silicate ?
pebbles/granules that develop in the coolant - so he drained it and
flushed it and sure enough there were handfuls of sand-pebbles
clogging it up. So I learned to use orange antifreeze - what do the
colors mean??


On Thu, 22 Apr 2004 20:11:48 -0400, "Jeff Morris"
wrote:

I'm in the middle of changing the antifreeze in my Yanmar 2GM20FC engines
and am
curious if I should change type.

I've been using Ethylene Glycol, following the advice of a Yanmar mechanic
who
said using Propylene Glycol would void my warranty. I've never been able to
verify that, and I'm now long out of warranty so I'm wondering if its time to
switch to the more environmentally friendly Propylene. I also think that
using
the easy to dispose propylene would encourage me to change more frequently.

Secondly, if I do change, do I have to flush out all of the old, or is it
sufficient to just drain it?

TIA, Jeff