Ti Kan ti at
Thu Jul 5 12:54:05 EDT 2001

audi90sq at writes:
> I just got the AC in my UrQ charged up yesterday, and
> was driving for about a half an hour to check it out. 
> Now, my car usually runs around 180 and shoots up to
> 210 at idle.  With AC I was running at 210 and when I
> got home and idled for a few minutes to cool the
> turbo, it shot up to 235 and boiled over.  Coolant
> bubeling out of my overflow tank.  1) I have not
> flushed the system in this car since I bought it a few
> months ago and 2) the coolant seems to be green (not
> red).  Will a good flush and some propper coolant cure
> my problem, or do I have other problems.  OBTW it was
> 120 out that dayl!

If your car is pre-1998 then the correct coolant is the good 'ol
green stuff.  Does your radiator fan work?  If that doesn't
run then fix that first.  If the fan works but you still get overheats
then check your coolant thermostat.  If the thermostat is good then
you probably have a clogged radiator.

Flushing the system is probably a good idea (you probably don't know
how old that coolant in the system is, but you should check the
basics first.

Use only phosphate-free coolant.  I recommend Autobahn from the dealer,
or Pentosin brand coolant.  Many of the off-the-shelf coolants from
auto parts stores contain phosphate (despite the claim that they're safe
for aluminum engines).  Most Japanese cars actually specify high-phosphate
content coolants.

01 S4 2.7 biturbo quattro
84 5000S 2.1 turbo
80 4000 2.0
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
  ///    ti at

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