Re: overheat light blinking

[Joe Yakubik <75363.2524@compuserve.com>]

The other day in regards to an overheat light post, I wrote:

My recommendation would be to check the antifreeze concentration (ethylene
glycol or specific gravity, etc) before just adding water or coolant (phosphate
free -- NO DEXCOOL -- it's incompatible!).


I probably should have checked all my facts first, but here goes....

I think Dexcool is a very similar product to a new type of antifreeze in Europe.
It may actually be the same stuff under a different name.  There was an Audi TSB
about this "new" antifreeze and I have also seen, and read, the warnings in
several auto parts stores.  

Simply put:  the new type of antifreeze (I am not sure if Dexcool applies or
not) IS usable in cooling systems, but only after the old system has been
completely and thoroughly flushed.  The two types of antifreeze do not mix well.
I am not sure of the chemical reaction/interaction between the two, but will try
to find out.  I equate the whole thing to silicon brake fluid vs.  DOT 4.  It IS
possible to use EITHER with their accompanying advantages and/or disadvantages;
but it IS NOT possible to use BOTH.  (Caps for emphasis, not shouting and
staying out of the brake fluid discussion)

My recommendation should have been clearer:  Do not top off your existing
coolant with Dexcool.

BTW:  the new antifreeze here is everything-free:  phosphate, silicon, nitrate,
etc

Sorry if I caused any anxiety.

Joe Yakubik