Date: Sun, 27 Aug 2000 10:38:11 -0500
Reply-To: John Rodgers <inua@hiwaay.net>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@hiwaay.net>
Subject: Re: Coolant change
Content-Type: text/plain; charset=us-ascii
Mark,
I use DexCool - (a GM Product I beleive) - advertised as good for two years. But
I change my coolant yearly. I takes no chances on my vans cooling system.
I learned the trick of raising the rear of the van to bleed the cooling system
from my mechanic, and man of 30 years experience with VW's. Bleeding the system
through the front bleeder valve is a bit of a PITA. Jack up the rear, with the
pressure cap off, run it until the cooling fan cycles several times. That way
you know the thermostat is open and coolant is circulating.Watch the coolant
tank. if there is a bubble the tank will burp, the level will drop a tiny bit,
and you can top it up then. Be sure to put coolant in the expansion tank and
reinstall the pressure cap.
You know that the low coolant warning light comes on at startup and sometimes
will stay on long after start up. Worrisome isn't it. Makes you wonder if
something is wrong. Try this little trick. Turn on the key so the engine lights
light up. The coolant light should be blinking. Do not engage the starter. Count
to 60, then engage starter. The light should go out. Do this on every start and
that silly light should never remain on after a sartup. It has to do with how
and how fast the system samples the resistance of the coolant between the prongs
on the coolant sensor. A fast start and cold drive-off will many times leave you
with a light that will blink for the next forty miles. Can be aggravating.
Be sure the coolant and the water mix is always by the book (Bentley). Otherwise
the resistance of the coolant will be wrong and much difference either way can
cause that light to come on as well as cause extra wear of the coolant pump.
Happy Trails!
John Rodgers
88GL Driver
Mark Dorm wrote:
> Down below you mention that you bleed the coolant with the tailend up???
> What is that? And you state that you change the coolant once every two years
> - I thought that we were supposed to be changing our coolant every year -
> plus does changing the coolant do anything to help the life of our hoses??
>
> >From: John Rodgers <inua@hiwaay.net>
>
> >Doug, the flashing light in the temp gauge in the instrument panel is the
> >low
> >coolant level warning light. It connects to the coolant sensor in the top
> >of the
> >coolant expansion tank.
> >
> >On the sensor in the tank, there are two bare prongs that stick into the
> >coolant. The sensor system operates on the resistance of the coolant
> >between the
> >two prongs. Several things can affect the resistance, and cause the llight
> >to
> >come on and blink.
> >
> >1) Obviously, low coolant will cause the light to turn on and blink. When
> >the
> >coolant drops to the point the sensor prongs are exposed, the resistance
> >between
> >the two will increase towards infinity, and the light will come on.
> >Solution:
> >add more coolant.
> >
> >2) If there is a crack in the sensor itself, that will affect the
> >resistance,
> >and the light will come on. I have had that happen to me twice. I just
> >replaced
> >the unit. Inexpensive, easy to do, available from Ron Salmon at The Bus
> >Depot,
> >Ken Wilford at Van-a-gain and others.
> >
> >3) Coolant to water ratio is out of balance. I can't say enough about this.
> >You
> >have to have the right amount of coolant in the water for the resistance
> >between
> >the contacts on the low water level sensor to be correct for proper
> >operation of
> >the sensor and warning light. Of the top of my head, I think I recall that
> >it
> >must be a 50-50 ratio. If the coolant is old, it can have it's effect.
> >
> >Coolant is no place to be chincy on the Vanagons. It's not THAT expensive,
> >and
> >good coolant helps keep the internal working of the cooling system free of
> >corrosion and increases the life of the coolant pump. I now use
> >bio-degradable
> >DexCool (orange color) in mine - good for two years - , and I bleed the
> >system
> >with the tail end up. Procedure works great for me, and I don't have to
> >hassle
> >the bleeder valve up front.
> >
> >Hope this helps a bit.
> >
> >John Rodgers
> >88GL Driver.
> >
> >
>
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