Date: Thu, 13 Jul 2000 09:01:44 -0700
Reply-To: Mark Drillock <drillock@earthlink.net>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Drillock <drillock@earthlink.net>
Subject: Re: Temp gauge/coolant Saga Con't.
Content-Type: text/plain; charset=us-ascii
I knew I shoulda left that can alone. My answer is that what logic is
really telling you is that if the other paths are blocked only the open
path will be used. This does not mean that ALL of the coolant will take
it, only the coolant that moves. The coolant trapped in the heating
system and in the head area at the heater ports is not going anywhere.
This results in hot spots in the head. Allowing the coolant to flow out
of the heater ports cools these hot spots. This hottest coolant does not
go to the radiator but gets mixed in with the much larger volume of
cooled fluid coming back from the radiator. You end up trading better
cooling of the hottest areas for a higher coolant temp overall. The fan
will run more but the engine will be at a more even temperature. I am
not advocating one rear heater bypass method versus the other, I am
merely discussing worms. I have quite a bit of experience towing a boat
with Syncro in 100 degree heat. To gain storage space I many years ago
removed the rear heater and used copper pipe to connect the ends. Where
I live the heater is not that important so reducing it's effectiveness
some is not a problem.
As a side note, in newer models VW designs the heater circuit so that
coolant ALWAYS flows at maximum through the heater core, even when the
heater is off. The heater temp is adjusted by changing the amount and
mix of air through the heater, not the flow of coolant. Of course this
means that the hottest coolant does not go to the radiator but instead
is mixed with the fluid coming back from the radiator. Do I hear an
echo?
Mark
Karl Wolz wrote:
>
> Watch out for those worms!
>
> Logic is telling me that if you remove the tees and close the front heater
> valve ALL of the coolant will run through the radiator, thus providing
> better hot weather cooling also. If you shunt the coolant through the tees,
> that coolant is returning to the engine uncooled.
>
> This may be insignificant, but driving around in 110 degree heat, I'll take
> whatever engine cooling I can get.
>
> Karl Wolz
>
> ----- Original Message -----
> From: "Mark Drillock" <drillock@earthlink.net>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Wednesday, July 12, 2000 10:44 PM
> Subject: Re: Temp gauge/coolant Saga Con't.
>
> > It won't make much very difference whether you plug the hoses or connect
> > them together. These hoses tap off from the heater hoses that go to the
> > front heater. If you connect them together you are allowing more coolant
> > to flow right back to the water pump and less will be available to go to
> > the front heater. In very cold weather you may regret not just plugging
> > them. The heads will have more coolant flow through them if they are
> > connected and this may help in very hot conditions. This is a can of
> > worms and I just opened it wider. I have done it both ways and it really
> > won't matter much except at the extremes.
> >
> > Mark
> > Katy wrote:
> > >
> > > Hi Volks
> > >
> > > Well we put in the lower temp thermostat and began the bleed process
> > > heaters on. Now here's where things get interesting. 5 min goes by
> > > and no coolant or air is coming out of the radiator bleeder. (getting
> > > warmer mind you) I'm in the back, coolant in hand by the expansion tank
> > > watching frequent bubbles escaping. 5 more min, 10 more, still no
> > > coolant bleeding out by the radiator. Something is wrong with this
> > > picture........Temp gauge is right around the middle, she's not hot.
> > > Start furiously looking around because it's not circulating (I think)
> > > Ah hah.....notice a little steam coming out of the rear heater vents.
> > > Open seat lid quick and throw everything out on the ground (I know "the
> > > council" knows ;o) A LITTLE (thank the vanagon gods) coolant near the
> > > rear heater core on the floor. And guess what IT'S GREEN with some
> > > orange around too ! We found the blockage and/or another leak. Check
> > > temp and right at 3/4th's. Things are starting to steam and bubble.
> > > Nothing out of the radiator bleeder, take out entire bleeder, she blows
> > > coolant all over, Expansion tank is now bubbling high and
> > > squirting/steaming up in the air. Temp still at 3/4 th's. (had Gabe in
> > > the drivers seat keeping the 2000 rpm and yelling out temp readings
> > > every 5 seconds) Close everything up and shut her down. Clamp hoses,
> > > connect together, take out heater core. (temp still reading 3/4 th's)
> > > Exciting stuff, burping Jezebel, huh???
> > > Preliminary evidence seems to indicate a tiny leak at both hose
> > > connections on the heater core itself. Larry will test tomorrow by
> > > plugging up one side, applying one half to one pound of pressure and put
> > > a liquid leak detector on it tomorrow. (this tester is used to detect
> > > leaks in liquid propane and vaporized propane so it should detect if
> > > there are any actual leaks in the heater core) Also will see if it is
> > > plugged up. We think???
> > > Other vehicle experience tells us that we can just connect the
> two
> > > hoses that go to the heater core together (without the rear heater core,
> > > if it is bad) and I can take off for my work in Michigan . Sure don't
> > > need rear heat in July. We can deal with it when I get back.
> > > If we're going to do something wrong (or already did) PLEASE
> council
> > > sirs and madams, tell us before we make it worse. I could find nothing
> > > in the Bentley about doing this, yet anyway.
> > >
> > > As always, thanks so much in advance for all replies.
> > >
> > > Katy
> > > (now humble servant to the vanagon god's)
> > > 89 Westy "Shame on Jezebel "
> > > NE Iowa
> >
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