I have written my story in the past, =
but I never
took the time to elaborate.
Here is my experience.
An Alternate Method to Costly Head =
Repair on
Leaking Vanagon Heads.
Like many vanagon owners, I was faced with the =
purchase
of a Vanagon that was wonderful except for a little coolant leak near =
one of the
heads. Understand this was "pre-vanagon newsgroup" for =
me and I
had no idea that this was a chronic problem when =
someone
used phosphated coolant.
If your experience is the same as mine, it =
starts out
with an occasional flashing light on the temp gage and a temp needle =
that is
pegged right after starting the van. This is from the level going =
down in
the coolant head tank and not from overheating as the engine hasn't had =
time to
even warm up yet. Its a panic the first time you see it and you =
check the
coolant in the overflow tank. Maybe low, maybe not. The low =
level
sensor is in the tank in the engine compartment (drivers side, to the =
left of
the "add tank") not the one behind the license plate. An =
interesting thing happens when the coolant is not too low, the =
light will
flash for a few minutes as the system sucks the tank low, and when the =
engine
warms enough to open the thermostat, the circulating action allows the =
tank
level to recover enough for the light to go out. Also, =
understand
that the cooling system fills itself from the overflow tank only when =
the system
is cooling down after you shut off a warm engine. Adding coolant =
to the
expansion tank (behind the license plate) will not immediately fill the
system. The contraction caused by cooling =
fluid sucks
coolant from the "add" tank.
One of the difficulties in identifying the leak, is =
the fact
that it may not be leaking while the van is at idle. Quite often, =
you need
to rev the engine while looking into the engine compartment to build =
enough
pressure for the leak to be apparent. You may not even have a =
puddle as
the leak is usually worse when you are under way. Before I =
realized this,
the only way I could tell where it leaked was to notice the funny =
discoloration
on the exhaust pipe where the coolant was squirting when I was
driving. After I knew generally where to look, I rev'ed the =
engine
and saw the tiny squirt coming out.
I found that I could buy some time =
before the
rebuild by adding fine saw dust to the head tank. In fact, I =
delayed the
rebuild for almost a year. Now before you blow me off as a hack =
that
dosen't care about maintenence, be it known that I have worked in =
numerous auto
factories and GM puts little cubes of sawdust in every car that goes =
down the
line. I don't recommend it for a long term fix, but it will allow =
you time
to study up and start saving your pennies.
This experience happened on an '84 =
that already
had 100,000 miles on it when I bought it. When I decided that it =
was time,
I dropped the engine and removed the heads. Upon discovering =
the
pitting, I sat and thought about it for a while. I have =
raced air
cooled VW's for a while and I'm not afraid to radically alter the heads, =
but
this was my wife's daily driver.
Option =
1) Mill the
heads: Due to the =
construction of
the waterboxer, if you mill the coolant sealing surface, you must also =
equally
mill the combustion surface. Great if your looking for =
performance
and willing to run racing fuel, but the increase in compression is not =
usually
desired on a daily driver.
Option =
2) Replace the
heads: Not even a consideration on my budget.
Option 3) Find a way to restore the sealing
surface. I got in touch with the JB Weld technical =
personnel
and they said that their product would withstand 500 degrees. =
Since the
heads are in contact with coolant, they can't get that high =
without first
boiling away all of the coolant. Figured I'd give it a try. =
Since I
didn't have a sandblaster at the time, I carefully cleaned out all of =
the
aluminum oxide (the white, scaly corrosion) with a dental pick. If =
I did
it again, I'd use a sandblaster after masking off the combustion
chamber, if only for the time involved. After =
the scale
was removed to my satisfaction , I cleaned the whole surface with a =
solvent
(carb cleaner). I purchased a fresh pack of normal JB Weld =
(not the
quick set) and applied a thin layer to the whole sealing surface and let =
it
harden for a day. After it had hardened, I took a file to =
the area
until I started to get close to aluminum. I had some areas =
that
didn't get filled well so I added more JB Weld to the areas that I had
missed. Let it harden another day and got it close again with a
file. Once I was close, I got some 400 grit sandpaper and taped it =
to a
flat surface. In my case, a piece of glass worked perfectly as =
long as you
don't drop the head on it. Start working the head over the =
sandpaper in a
figure eight motion and try to keep the sanding even. Look often =
at your
progress and adjust your pressure or motion in able to keep the removal
even. Once you start getting down to the original aluminum, you =
should
have a surface that is flat with the pits filled in. If you have =
any
remaining holes, you may have to re-apply and re-sand. I =
purchased
an OEM gasket set and it had the black sealant for the seals and the =
yellow
sealant for the bolts. About $200 for my gaskets. =
While I had it down for the repairs, I =
replaced the
bearings, seals, and rings. The crank measured EXACTLY the Bently =
spec's
and I did nothing to it. I did re-lap the valves manually and that =
was
about it. The piston pins can be a bear if you don't have =
the
puller, so be careful to set both pistons to mid stroke to avoid pulling =
the
pistons out of the cyclinders if they stick to the head. I have =
some ideas
if you run into a pin removal problem but that's not the subject of this =
article. Other than that, pretty straight =
forward.
The story would end there except that a month later =
my wife
accenditally pulled it into 1st gear while doing about 65 =
mph. The
engine came down again to replace 4 exhaust valves as they all touched =
when the
engine over-rev'd and I had 0 compression. No other damage. =
Did the
work with the engine in the van. Re-used the head seals with =
sealant that
I had left over.
That engine has another 120,000 on it and it has not =
leaked a
drop from the heads. I am no longer afraid of leaking =
Vanagons. In
fact, I look for them as they are good engines when fed and cared =
for
properly. Once you are comfortable with this method, =
you can
find some deals. Basically a total rebuild while repairing the =
leaks for
under $500 and some time.
Hope this helps when deciding which =
way to
go....
Good =
luck
Mark Rokus
I would imagine that the material that has =
been posted
is due to what has been provided in the past. I think it would be =
great if
you could provide me with an article on the JB Weld method, as I know =
that it
has been popular with many List members. I would be more than =
happy (and
perhaps even grateful) if you could write something up and send it to
me.
Thanks again,
Brent Christensen
'89 GL Syncro Westy
Santa
Barbara, CA