20V After-Run System Consensus

QSHIPQ at aol.com QSHIPQ at aol.com
Sun Jul 27 15:53:20 EDT 2003

[ Picked text/plain from multipart/alternative ]
You can't change "values" of the afterrun temp sender.  The 20vt motors are
set to a higher threshold, it's not adjustable "back" IMS.  If it turns on at
all, it's working, though you might have a bad afterrun relay (I doubt it, or
it usually never turns on).  The advantages of the water cooled turbo so outdo
the oil cooled that really the "afterrun" is redundant, and a good battery
power drain.  Most other marque WC turbo systems don't use an afterrun at all, so
don't worry about it.  Chances are good too, that since you replaced just
about all the other components, the car now runs cooler and has a higher cooling
capacity reserve, so the chances of temps getting into the "afterrun" trigger
are a lot less.  S cars work the same way, rarely does the afterrun come on.

If you are used to the 5ktq afterrun circuitry/activation the 91 200 is low
frequency in comparison.  Attribute that to a better cooling system (read: a
brag, not a complaint) audi put into the 20vt cars.


Scott Justusson
QSHIPQ Performance Tuning
Chicago IL

In a message dated 7/27/2003 4:22:52 AM Central Daylight Time,
BriceW at webtv.net writes:

I have about got the WHOLE cooling system changed over to new.
What I have NOT changed yet is the radiator fan motor, blower motor and
the heater core.
Everything else is brand spanking OEM new. New 1st,2nd and 3rd stage
New after-run switch, new MFTS with new connectors and wiring, new blue
3 stage resistor pack, new after-run aux. cooling pump relay, new
radiator and aux. radiator, all new hoses and connector clamps, new
water pump and all of the of the mandatory things associated with that
job, new coolant tank reservoir, new mounts,etc.
My after-run system is not operating properly. At least not as I
remember former Audis operating.
The after-run fan and pump seem to never turn on. It turned on yesterday
for the very first time in a long time after a 20 minute drive on a very
hot day with the air conditioning on which turns on the high speed fan
and cools the system.  I am used to the Audi after-run system turning on
after a short drive in normal temperature without air-conditioning, This
is my 5th Audi.
My question is.
What is the normal after-run time for our cars?
I almost want to try the lower temp after-run switch as I don’t feel
that my after-run system is operating properly.
I know that Scott does not recommend this switch as it lowers gas
mileage. I live in Kansas and shouldn’t need this lower temp switch.
What is the NORMAL for the after-run fan and pump to turn on? NORMAL in
Summer and in Winter.
Maybe I am be to exacting about the after-run system but I feel that it
is very foundational to the whole car.

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