Re: [alfa] Overheating 156

["Guy Weller" <Guy.Weller@xxxxxxxxxxx>]

Darryl, Mike, Timand thers who gave advice about this overheating problem.
I have been using the 156 for work today which means driving some 100 miles
or so in the English Lake District.  Mixed driving from fast clear roads to
traffic tail-backs to 1:4 mountain passes.  So plenty of time to "play" with
the problem.

So this is what I find....
I don't think it is the guage.  I can get it to rise and fall using the
heater fan on full roast setting.  It could be the sensor as the temp does
seem erratic.  On the first 20 miles the temp behaved absolutely normally.
I then stopped for a while and when I re-started the temp rose within 2
miles to near to red light warning level.  Switching on the heater brought
it down again.  Given that both the warning light and the guage indicate
overheating, then I think it is not a guage problem.

I now suspect that although the fan works, it may be that it is cutting in
and out erratically.  So it could be an intermittent switch or sensor
problem.  I need to try and rig up a test for it.

This doesn't rule out the water pump but I am still leaving that possibility
till last. Incidentally the water pump is on the toothed belt on these
engines so it cannot be belt slipping.  It could be a loose impellar though.

Guy
----- Original Message ----- 
From: "Guy Weller" <Guy.Weller@domain.elided>
To: <alfa@domain.elided>
Sent: Monday, September 15, 2003 9:39 PM
Subject: [alfa] Overheating 156


> Hi, I mentioned this overheating problem a little while ago and got
various
> bits of advice.
> Having now tried the  various things sugested, I am still left with an
> overheating car and am looking for further opinions about the likely
cause.
>
> The car is a 4 year old, high mileage (137,000) 156 TS 2.0l.  It has been
> fully serviced and maintained by an Alfa main agent in the UK.  Never
missed a
> service ever 6,000 and always with 300 miles of the due mileage.
>
> It has a tendancy to run hot. That is with the guage on 3/4 (110degrees)
> rather than on the mid-point of the scale (90 degrees)
> At a steady 70 it will run approximately on the mid-point of the scale.
If I
> slow down for traffic or climb a hill the needle rises to beyond 3/4 mark,
and
> occasionally so that the red warning light comes on.  Ambient temp round
here
> is 55 to 65 degrees F at this time of year. It is not loosing coolant.
>
> The fan is coming on, although I find it difficult to tell exactly when
whilst
> driving as I cannot hear it. I maybe need to rig up an indicator lamp so I
> know when it is running.
>
> I have emptied and back flushed the radiator and complete system.  It was
> pretty clean (no sediment) and water seems to flow freely through the rad
> core.  The radiator seems fine to me.
>
> I removed the thermostat and boiled it up on the kitchen stove with a jam
> thermometer.  It began opening at about 82 degrees and was fully open by
about
> 105 degrees. It closed evenly as I let it cool down again.  I think that
is as
> it should be.
>
> I am running out of ideas.
>
> Guy
> --
> to be removed from alfa, see /bin/digest-subs.cgi
> or email "unsubscribe alfa" to majordomo@domain.elided
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided