Date: Mon, 14 Jan 2008 16:22:30 EST
Reply-To: FrankGRUN@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Frank Grunthaner <FrankGRUN@AOL.COM>
Subject: Re: Pointing out the Facts on Vanagon Diesels - why breaking!
Content-Type: text/plain; charset="US-ASCII"
In a message dated 1/14/08 3:01:07 AM, scottdaniel@turbovans.com writes:
> How do you explain all the blow engines then ? just lack of decent
> maintenance ?
>
>
Scott,
As you saw from my previous comment, blown vanagon diesels are not part of my
experiential database! But a few observations come to mind. On the issue of
vanagon engine blocks ventilated with broken rod bits protruding, in my
experience (and I've seen between 20 and 30 over the years in my Saturday morning
junkyard constitutionals) they have all been waterboxers mostly 1.9l units. Of
course those are also the majority of vanagons I see in the junkyard. Of the
different junked diesels I have seen, they were oil encrusted but sidewallus
intactus. No busted cases on the air cooled units either.
I have seen a large number of functioning diesels. On every one, with my one
ride excepted, the belt driving the waterpump has been very loose. Often
accompanied with complaints about alternator charging. As you will recall, the
tightening sequence involves shimming the crank pulley as per the air-cooled
beetles. I would argue that this would lead to overheating, then head warpage, then
water in the combustion chamber then bang. I have had several discussions
with diesel mechanics over the years and they often pointed to air in the cooling
system and subsequent head leakage/warpage.
The second common issue I have seen is oil overfilling. This is often
associated with oil everywhere in the back of the van with loss of the rear seal and
often the front one as well. The vanagon is very susceptible to oil level
errors when the level is checked on a graded surface via the rear pull dipstick.
Aeration is a very serious issue at these engine speeds and temperatures
leading to more than an order of magnitude reduction in lubricity.
I have also seen burnt-off glow plug ends in junkyard machines. Tragic waste.
I have often encountered air filters that are virtually impassable. This is
often correlated with heavy smoke and oil puddling in the intake tract. Both of
these conditions lead to heavy coking in the combustion chamber. Diesels also
undergo a form of detonation which can add sever shock pulses to the rod.
I changed out the timing belt at 40,000 mile intervals because of the engine
room temperatures and because I saw cracking in the belt driven surface in my
monthly inspections. I was told by dealer mechanics about the large number of
diesels that were mistimed by one or two teeth. They concluded that the belt
was marginally loose and had jumped a tooth on rapid downshift induced
deceleration. Very dangerous for longevity.
All of the above, I attribute to poor maintenance on the part of the owner or
servicing mechanic.
Finally, under the category of owner induced mistreatment, I argue that
lugging the engine (so much of the American driving habit) is terminal. The diesel
has a very wide torque band coming in a very low speeds. Lugging together with
an aerated or depleted oil condition will generate bearing seizure and rod
sheer. The diesel equivalent of detonation is more pronounced under high load,
low rpm conditions.
However this is (as I am fond of saying) is anecdotal. No careful analysis of
cause and effect with controlled or well monitored conditions. Many years
ago, after first acquiring the Vanagon diesel, I subscribed to several
professional mechanics newsgroups. Here, there was often discussion of the results and
statistics of manufacturer warranty claims. Look at the Chevy warranty claim
problems on the V6 engines. Dwarfs VW's production figures. But this the life
and death analysis of any manufacturer. The general tone of issues on VW was all
focussed on the waterboxer. Of course the diesel penetration was low. Still,
there is where real life test data lie.
Finally, finally, finally, I recall a conversation with a VW engineer from
the Hannover engine lab that commented on the relative cost holdback for
warranty claims on the diesel vanagons services in Germany. He pointed out that the
cost assignment for the N/A diesel was less than half that of the next closest
engine group (the 1.6l gasoline air cooled unit). The turbo JX engine was
next, followed by the waterboxer 2.1, and the wbx 1.9 came in as most expensive to
warranty. Point is, most reliable, in Germany, was the 1.6l N/A diesel.
My ill-informed contribution to the noise level!
Frank Grunthaner
**************
Start the year off right. Easy ways to stay in shape.
http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
