a horror story RE: Evans Coolant - S4 Back in Service,

["Brandon Hull" <brandon@cardinalventures.com>]

I'm watching this thread with interest, since the "ersatz S2" is also
running Evans coolant, which George Baxter swears by, and has used in
numerous quattros including his own 5000, '91 200, and urqs.  I'm at a
disadvantage in comparing the 3B with Evans to the 3B without, since it was
installed in the car from the outset of the engine swap.  However, I've
noticed what I regard to be wide swings in coolant temperature.  At highway
speeds, the engine never seems to get fully warm, with the water temp needle
remaining at the bottom third hash mark.  Oil temp seems ok at 100C or so.
In traffic, however, the water temp swings up toward between the half and
two thirds area, with some small increase in oil temp.  I don't like these
swings, and worry that the engine is running too cool much of the time.  Now
I worry that the hot swings might lead to other problems.
The virtues of Evans for a high strung turbo engine (very high boiling
point, elimination of flash hot-spots resulting from spot vaporization of
coolant in the head, which could cause detonation or other damage)  seem
worth the experimentation, but from George's description to me of Larry's
problem, the S4 clearly did not like it.  Igor, what has been your
experience?

Avi, why did you have to replace radiator and heater core?

Brandon Hull
'91 ersatz S2

Avi Meron wrote:


Lawrence,
I too have experienced the same problems,
The results (damages)of converting to Evans are:
6 gallons of Evans coolant
1 water pump
1 timing belt (if you put in a water pump, might as well do the rest)
1 timing belt tensioner
1 after run coolant pump
1 radiator
1 heater core
1 pressure cap (Vanagon type)
1 thermostat
There might be a few more odds and ends but I can't remember them now...

The car (5K turbo Q, 2 bar boost), experienced overeating problems from the
first day of converting to Evans, numerous attempts to get in contact with
one of the list members that has performed  the conversion failed.

If anybody cares to know more technical details of the conversion let me
know.
My conclusion is that the Audi water pump (in the configuration that we have
in our turbos) can not pump the thick Evans coolant, my Audi contact (Mike
at Inglostat West) confirmed the theory by describing similar symptoms when
100% coolant (the regular water base) is used.

Avi

- -----Original Message-----
From: owner-quattro@coimbra.ans.net [mailto:owner-quattro@coimbra.ans.net]
On Behalf Of Lawrence Bardfeld
Sent: Thursday, December 24, 1998 10:50 AM
To: 'Quattro List'
Subject: Evans Coolant - S4 Back in Service

Just in time for the new snow here (Philly), I've got my car back, the
Evans coolant flushed out and replaced by conventional water-based
coolant.  My mechanic, who had previously used Evans successfully in a
variety of Audis, thinks that perhaps due to its higher viscosity and
the S4's cooling system the two were just incompatible (resulting in
my 2 turbo coolant pump meltdowns in 2 days).  My question: what might
be different (thinner tubing?) in the cooling system of a car such as
mine ('93 S4) that might account for the difference (compared, e.g.,
to a 5000)?

And a merry Christmas (and thanks) to all!
Larry Bardfeld