Date: Mon, 6 Mar 2000 08:14:39 -0600
Reply-To: Chris Smith <chris.smith@AQUILA.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Chris Smith <chris.smith@AQUILA.COM>
Subject: Gas heater fix (long)
Content-Type: text/plain; charset="us-ascii"; format=flowed
There have been many posts dealing with various fixes for the Gas heater,
but I thought that my weekend might help someone else working on their heater.
The Problem:
Last week the heater quit about 1/2 way to work one morning. This may not
sound bad, but it was 45minutes without heat in 30deg temps. The fan would
still run, and I could hear the ticking of the fuel pump, but the "jet
engine" sound of the heater was missing, as well as the heat.
The Solution:
Day 1:
Pulled the pan to check for fuel output. The fuel filter we installed last
summer when the engine was replaced looked nice and clean.. so much for the
easy fix.. while the van was inside we tried to start it. Raw fuel smell
filled the shop and drove us outside for a while to let the shop
air-out. Next we pulled the spark plug wire from the spark/glow plug and
checked for spark by starting the heater. No spark! Testing the coil
power + terminal showed 12v, and there was intermittent continuity between
ground and the terminal 1 (-) wire going from the coil to the fan
motor. Seems that it's the coil. Since it was getting late we called it a
night and tried to find the part.
Day 2:
Called 3 more places, sent multiple emails, gave up and started searching
archives. Luckily I found an article about using a stock coil for the
heater, and started plans for working on the heater all day Saturday.
Day 3:
got up early, took kids to grandmas house for their overnighter, froze in
van, got ready for battle. Pulled the pan again, and started mounting the
new coil. about 1 hour later had the new coil in and gave it a try. No
Heat.. hmm... now what.. Pulled the coil since I must have screwed
something up and redid all the tests. Power, continuity, and this time
spark.. so why wasn't it lighting?..
At this point it was time for lunch and another look at the Bentley manual.
Finished lunch and went back under the van. Now it was time to pull the
spark/glow plug and see what was up. Here came the fun part. The plug
takes a standard 21mm spark plug socket to remove. I bent the heater
element tabs up to slip the socket over the plug, got he socket on, but
then found that wrench handle wouldn't fit. Plus my large wrenches were
out on loan. In desperation I tried the trusty vice-grips. ( I really
didn't want to have to buy one wrench from sears and drop over $10 for a
spare tool) I was able to get them on the base of the plug and give it
about 10 degrees of movement...
Joy of Joys.. I worked! the plug was able to be unscrewed just by
fingertips. Once the plug was out, I saw that is was horribly fouled. Not
one hole was open and there was no sign that there was a coil wrapped
around the insulator. I tried calling the local VW parts guru, be he has
no source, the flaps try to sell me W8AC (not even type 4 plugs...ugg) and
the dealer has no idea what I'm talking about since they have just switched
over to a computerized parts system and are not willing to dig out the
fiche nor have they been able to look-up parts that they haven't been
trained for. From this I learned 2 things. One, I'm going to have to find
a way to clean this plug, and two, I'm not buying my next VW from the local
dealer, nor get it serviced there.
I was stumped as to how I was going to clean the baked-on carbon, so I went
to the FLAPS to see what they had. I found some Gumout Combustion Chamber
Cleaner, and gave it a try. I poured the bottle into a clean coffee can,
dropped the plug into the solution and gave it an hour to soak. Then I
went back and went after the carbon with a nylon detail brush and some
brake cleaner. The plug came so clean it almost looked brand new. When it
was reinstalled the heater fired up after 10 seconds and spit-out a ton of
black smoke. The smoke cleared after a minute, and since then has been
starting either immediately when warm, or within a few seconds when cold.
I hope this can help someone trying to get a heater working. I found the
Bentley manual indispensable for research, photos and wiring
diagrams. Also the archives were great showing a regular coil could be
used in place of the original coil. Total cost for repairs was 1 spare
parts coil, $4 for cleaner, $2 for brake cleaner spray, and $3 for new pan
hardware.
Chris Smith
Director of Smoke and Mirrors
Der Busbesitzer Gruppe