Date: Fri, 1 Jan 2010 09:52:04 -0500
Reply-To: Woody Halsey <WHalsey@SYA.ORG>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Woody Halsey <WHalsey@SYA.ORG>
Subject: Re: one last effort to get the temp control gauge under control
In-Reply-To: A<10212106.16467.1260909599371.JavaMail.mcneely4@127.0.0.1>
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Well, after desultory efforts (work, kids, holidays made sustained
attempts impossible) to figure out the "overheating" problem, I think I
can report success. As always with Old Systems (such as my all-too-human
body) I think there were multiple factors; and several points along the
way where my surgeon wife's favorite expression ("true, true, and
unrelated") might have been appropriate. I probably have more new parts
than I needed, but things seem to be working and the mechanic who
installed them says he'll not charge me for any labor, since he failed
to solve the problem. So, I now have:
o New radiator
o New temp sensors (both)
o New water pump
o New thermostat
o New little cross-over pipe between the thermostat and ... not
sure where it goes, but the old one had a small hole in it
o And a seemingly well functioning cooling system!
The temp gauge shows normal, gradual warming now and settles in just
over the warning light (that blinks normally at start-up, then goes out)
at highway speeds. The radiator fan goes on if the engine runs for a
while in the driveway. The front and rear blowers produce decent heat
after warm up. There are no signs of overnight leaks on the garage
floor.
Ultimately, all I did was execute the simplest bleeding procedure, as
recommended by savvy list members. After a failed attempt with front end
up on ramps, I succeeded with the V'gon level in the garage. The key
thing, as many have insisted, was to start with a cool engine and to
keep the RPMs up as I was adding coolant to the expansion tank. The
"friend" who did the best work for me in that department was NOT my
bro-in-law (who earned his glass of wine for nothing!) but an
appropriately sized piece of firewood positioned like a moderately heavy
foot on the accelerator pedal. I ended up adding two full gallons of
coolant and about one gallon of water before the mixture flowed free of
bubbles from the radiator bleeder. (I was surprised at how gentle the
stream was, just hugging the radiator casing. I didn't even notice it at
first in the ill-lit garage.) And I managed to purge all the air despite
the fact that the engine compartment bleeder valve broke and got
replaced years ago by a simple hose connector.
Conclusions: The explanation for the pegging gauge was "mechanical"
after all, but probably nothing too complicated. At the outset it was no
doubt the hole in the little cross-over pipe that was allowing coolant
to leak (hence, probably, the smell of warm coolant I'd been noticing,
literally, for years when the engine was running), lowering the level
below the probe in the expansion tank, and letting air into the system.
Then, after all the new parts were installed, it was the fact that the
mechanic had failed to refill the cooling system properly, adding only
about half what was needed and leaving huge amounts of air in the pipes.
Once the air was out, the coolant in, and the expansion tank filled to
the brim (as Ken urged), the gauge started behaving normally again.
I hope I am right. I haven't driven very far yet though, so stay tuned
... I still may purchase the Block Tester, to confirm there are no
exhaust gasses in the coolant; but I have not been able to find one
locally. I did find the NAPA part # on-line so may have the local guy
(who had no idea what I was talking about) order one
Now if I can figure out why fuse #1 keeps blowing ...
Woody
83.5 V'gon
Haverhill, MA
W. W. HALSEY II
President
T 978.725.6828 ext.115 M 978.204.5795 www.sya.org
439 South Union Street, Lawrence, MA 01843
SCHOOL YEAR ABROAD
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Dave Mcneely
Sent: Tuesday, December 15, 2009 3:40 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: one last effort to get the temp control gauge under control
Well, back in the day, on our old cars, we could start the engine, let
it warm up, and open the radiator cap to see if flow occurred. Can't do
that now (and haven't been able to in a long while). If there is no
flow, that suggests a stuck thermostat (a new one can be bad). The red
light is supposed to flash on startup, then go out. If the engine is
not yet warmed up, then it is not overheated (duh). But that doesn't
mean you don't have a problem.
Items you did not mention include the fan switch (it's on the radiator,
lower right as you look at the van from the front). If the guage pegs
as soon as the engine is on, I'd suspect electrical, regardless of your
mechanic's opinion. Check all the connections, as well as the fan
switch. The guage itself could be bad, too. Which sender did you
replace, the low coolant sender on the pressure tank, or the temperature
sender on the thermostat housing?
Good luck, David
On Tue, Dec 15, 2009 at 1:02 PM, Woody Halsey wrote:
> Well, after a couple of years of minimal use and maximal body work (my
> wife says that the V'gon is like an aging woman with a lot of face
> work:
> beautiful on the outside but ...) I decided to fix the
> overheating/pegging temp gauge problem once and for all. New
> thermostat, temp sensors, water pump, radiator and fresh fill of
> coolant have NOT solved it. The mechanic who is doing the work for me
> now says he thinks a head gasket job is in order. Does this make
> sense? * There is no leaking around the gasket. * The
> expansion tank is filled to the brim. * The temp gauge pegs over
> and the red light starts flashing as
> soon as the engine is turned on. Can it be "overheating" if it is not
> even "warmed up?" * Mechanic states there is no flow of coolant
> through the system.
> (Is it possible to check that with a stethoscope?) * Mechanic
> insists that the problem is mechanical, not electrical.
>
> Awaiting your wise suggestions before spending any more money,
> Woody
> 83.5 V'gon
> Haverhill, MA W. W. HALSEY II
> President
> T 978.725.6828 ext.115 M 978.204.5795 www.sya.org
> 439 South Union Street, Lawrence, MA 01843
> SCHOOL YEAR ABROAD
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