Date: Mon, 14 Jun 1999 23:39:26 -0700
Reply-To: Coby Smolens <cobys@WELL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Coby Smolens <cobys@WELL.COM>
Subject: Re: Frustration: 85 Vanagon Cooling
In-Reply-To: <MEAJNCCNCOGDBAAA@mailcity.com>
Content-Type: text/plain; charset="iso-8859-1"
The easiest way to assure yourself of no combustion gases in the coolant is
to have it tested for HC, so:
a. Go to your local service station and get 'em to sniff the air at the top
of the overflow reservoir. It needs to have been closed during driving for a
while, a good half hour at least, over hill and dale. By "sniff" I'm
referring to the use of an exhaust gas analyzer, inserted into the fill
opening of the overflow reservoir immediately after opening the top (you
don't want air to dilute any hydrocarbon content). If this test comes up
with ANY HC (basically unburned fuel) at the top of the overflow reservoir,
you've got leaky head gaskets or a cracked head. Well, your van does anyway.
OR,
b. Go to your local NAPA (or other good-quality) parts store to purchase a
chemical "block test kit". This does the same thing as the exhaust gas
analyzer with a little less accuracy. It's a kind of litmus test for HC.
Using a suction bulb you draw air from the top of the cooling system through
a glass tube containing a solution of chemical indicator fluid which changes
color in the presence of HC. If necessary use a squeeze bulb thingy (like a
turkey baster) to remove enough coolant so that you have two or three inches
of air at the top. Drive the van thirty minutes of so, under hard load at
least part of the time (combustion gases get squeezed into the cooling
system through head gaskets/seals or cylinder head cracks easier under heavy
loading). Let it cool down enough to allow you to remove the top of the main
reservoir (carefully, with protection, such as a thick rag). Then you insert
the lower (pointy) end of the testing tube into the air, NOT the coolant, at
the top of the reservoir. Using the bulb you carefully draw air up through
the tube and watch for a color change. If the color goes from blue (it
starts out blue) to green or yellow, you've got yourself a leaker.
Running without the belts is certainly going to add vapor to the system,
since you'll be running with no waterpump, which will allow coolant to boil.
It's possible that one of the heads was cracked at the time of the reseal.
You can check for this to some extent by doing a leak-down test as suggested
by Darrell Remember that to do this test you need to have the engine at top
dead center of the compression stroke at each cylinder respectively. Also,
using 100 psi in the cylinder is a tricky business. The piston must be
EXACTLY at TDC or it will be shoved (rather violently) back down the hole.
Be very careful! I know people who nearly lost appendages trying to hold the
engine at TDC with a wrench while doing this kind of test. I recommend using
a regulated type leak-down tester, or in some way controlling the amount of
air you are inserting. You should be able to gradually increase the
pressure...
Of course if there's a crack it may not show itself until it's hot. If
you're getting visible bubbling with the engine running, you can pull
injector plugs one at a time while checking for HC (helps to have a friend
at your local service station for this one) with a gas analyzer. If the HC
count drops to nothing soon after pulling the plug on an injector you've
found the bad hole.
NOT that I'm suggesting you've got any combustion gases in your cooling
system or anything! NO, no, no -- Far be it for me to imply anything of the
sort! We want to keep a positive outlook here after all. It's probably a
plugged radiator, or maybe even the mythical Stuck Thermostat.
Coby
Valley Wagonworks
"Intimately acquainted with VW Vans since 1959"
Volkswagen Bus, Vanagon, Westfalia and Eurovan
Repair and Service Specialists
1535 Sir Francis Drake Blvd., San Anselmo, CA 94933
Voice:(415) 457-5628
Fax: (415) 457-0967
http://wagonworks.com
mailto:contact@wagonworks.com
On Monday, June 14, 1999 1:49 PM
Michael Orbon wrote:
> Sent:
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Frustration: 85 Vanagon Cooling
>
>
> That's the answer I'm hoping against.
>
> Right. I'll definitely take it to the same shop that just did the
> head gaskets if it tests bad again.
>
> What about removing the belts and running the engine to see if
> gas gets into the coolant?
>
> Mike
