[V6-12v] Audi heating - bone head moves --

[Kent McLean]

Clive Young wrote:
<long, sad story snipped>
> So I am completely back to the beginning , I think I'll replace 
> the core in the summer if I can get an aftermarket one cheap! 

Thank you, Clive, for being human.  I, and I suspect most on
this list, can relate to having made similar dumb moves.

My 2 cents on the heater core --  I'm confused by your description
of how the temp gauge reads: "thermostat opens at about the first
of the tiny dots on the temp display if you look carefully. After
that engine cools right off as it is suppose to and heat comes on."

I'm thinking "normal" is when the temp gauge hits the first line
(dot) on the display and stays there (at least on the 2 Audis I
have owned, they hit the first, low end of the gauge).  If after
that "the engine cools right off", I don't think it should; it
should hit the normal range, stay there, and not drop below it.

2nd line of thought: I don't think the heater core would/could/should 
affect your temp gauge that much. That is, if the temp gauge reads
"normal" until you ask for heat, and then the temp gauge drops,
then that isn't normal, in my experience.

If I was desperate (and it sounds like you are getting there),
I'd circumvent the heater core temporarily, maybe by putting a
new hose in a loop where the older hoses to the heater core
attached to the engine.  I could then a) see if the temperature
gauge reads normal and stays there when the engine warms up,
and b) I'd try to flush the heater core with a garden hose
feeding the now-detached heater core input hose, and c) try
to back flush the heater core with a garden hose feeding the
detached heater core output hose.

If the engine temperature gauge acts normal (the needle slowly
moves to the normal range and stays there), then I'd replace
the heater core.  If the temperature gauge needle continues
to fluctuate (drop when you turn the heater on) as it does
now, then I don't think chaninge the core will fix it.

Those are just my educated guesses.

--
Kent McLean
'94 100 S Avant, "Moody"
'89 200 TQ, "Bad Puppy" up in smoke