Date: Sun, 27 Aug 2000 11:28:36 -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: multipart/alternative;
Mark,
I use the brand name - DexCool - (a GM product I beleive) which is rated for
being good for two years. I still change my coolant every year, regardless of
the ratings. I takes no chances on my cooling system.
I now bleed the cooling system --most of the time-- with the back end of the
vehicle jacked up off the ground or sitting on a steep grade. I don't bleed
throught the bleeder valve up front which is a bit of a PITA. I first learned
this little trick from my mechanic, an old timer who has been working VW's for
30 years. Run the engine with the pressure cap loose or off until you are
satisfied entrapped air is clear. You can tell when air is released because the
level in the coolant tank will go down a bit. Run it until your cooling fan
cycle several times. When done top the coolant tank, bring the overflow tank up
to proper level, and drop the van down. You should be ready to roll.
One last thing. The low level coolant light always comes on when you turn the
ignition key, right? Well, sometimes it won't go out, yet I know full well that
there is coolant, and nothing is wrong....but that light is worrisome. I have
found that if I will turn on the key but not engage the starter, and count to
60, then engage the starter, the light will either go out before the start or go
out when it starts. I have not read this anywhere but it appears that the system
samples the resistance of the coolant solution before each start and if you
start to quick before the sampling is done, it doesn't have the complete data,
so when the starts occurs it's not ready and the light stays on and may stay on
for miles before the process is completed and it is determined that in fact all
is well with the coolant level.
So, I have learned to be patient, count to 60, and
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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