Date: Sun, 8 Aug 2004 15:42:20 -0600
Reply-To: jbrush@AROS.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Anonymous Digest <jbrush@AROS.NET>
Subject: Noisy lifters, rockers, at startup, etc (long)
Hi all,
I bought this up on the air cooled list, so if Wil, and others who offered to
help recall it, I don't want you to think I am second guessing, or doubting your
expertise. I appreciate the advice, and am just searching for more opinions and
theories.
My air cooled, at 200K, is starting up with clacking lifters/rocker arms way too
often. Circumstances only allow me to drive it three or four days each month, so
for much of this year, it sits for at least several weeks between starts. In
case anyone is curious, its an insurance issue, as I cannot afford to insure it
right now, but they do allow me to drive it four days a months, for a tiny flat
fee, but that means I cannot just drive it around the neighborhood every few
days to keep it running happy, so I get one or two weekends out of it, if I plan
accordingly :-)
I take a long trip, it runs great, and I sure feel badly about having to let it
sit for so long before I can drive it. I do so enjoy it. :-) It sits for about
two an a half weeks, and when I finally start it up , I get more than just one
lifter/rocker arm tapping, there are a mess of em "not happy" and it takes
nearly twenty minutes of cruising easily through the neighborhoods to quiet it
down. Not long ago, before I took it out to try and silence it, I put in about
half a quart of Marvel Mystery Oil, as that has helped on rare occasions before.
Did it help? Certainly not within five or ten minutes of idling. Its still in
the crankcase, and I still have the issue when I start it up, so I am not sure
it did much good.
When it is so gosh-awful- noisy, it still runs just great, although it sounds
like a V10 diesel, and its a bit embarassing to get those looks from folks as I
go by, or sit at a light.
As an aside, it does blow a lot of oil on trips, and so I am quite certain that
I always have pretty fresh oil in the crankcase, as it gets a full change on a
1200 mile trip, and I ditch it, and the filter, after every adventure. I feel
certain that it has never suffered from dirty oil over its lifetime, and that
what is in there now is pretty fresh oil. Its been changed more than four times
this year so far, and the problem remains.
I have taken to starting it up and letting it run for about ten or fifteen
minutes every other day, in hopes of avoiding such stress with weeks between
starts. After two days, it will start up noisy, quiet down in ~15-20 secs, but
for a bit of a tap. I let it idle at about 1500RPM for ten minutes or so. By
that time, it is running as quiet, and as "happy sounding" as it ever has, the
oil temp is around 150 or 160 by then, in the summer heat.
I have tried cranking the engine with the spark disconnected in order to get
pressure up before letting it start, but I guess there is just not enough oil
pressure at that slow speed to do much of any good. Used to help, but not
anymore.
Given the cash, I would just buy a new motor. Till then, I would like to solicit
ideas and opinions, especially from those who "suffer" from this, and who have
been inside the 2.0L aircooled motors. I am more of a V8 expert, so what I know
about the internals of these beasts, I have learned from you folks.
I switched from the FLAPS Bosche filters to the Mahles from our online vendors a
few years ago, although I don't blame the filters. With regards to the filter
and the pressure valve on an air cooled engine, I fail to see the need for it,
as the filter sits vertical, and not tilted as on the water cooled motor, and is
always full of oil, so I have no idea how such a pressure valve can have any
effect on this engine. I'd like to hear the technical, oil flow explanation for
it, if it is really considered critical. That notwithstanding, I use the better
ones anyway, but so far, I see no proof that they do any better regarding this
problem.
My biggest concern is the excessive wear and damage I am doing to the engine,
and I am soliciting thoughts as to what is the lesser of the evils.
In my mind, the noise I am hearing is the clatter of the rocker arm being
slightly "loose" if you will, as the lifter pumps up. Its not much of a
clearance deviation, but I assume its enough to make the racket. I can't see
adjusting the lifters, as they do quiet down eventually, and the motor is as
smooth as that "baby's butt" we all relate to :-) Would an adjustment seem
necessary, or useful?
Is that noise actually what I think it is, or is it a cam/lifter issue that is
stressing the cam lobes, and gonna fail one day if I let it continue? Its loud,
but I am assuming its the rocker arm wacking the valve stem/spring, as well as
the pushrod. Yes or no?
I use 20-50W exclusively, cannot afford to use synthetic as the engine has a
"blow by" problem and blows a lot of oil out the main seals and probably other
places. Plus, changing over in a motor this old seems like a bad idea.
It would seem to me that a lighter weight oil would be called for, to pump up
the lifters faster, but I am just guessing about that.
Since noise like this is caused by something stressing out, or being out of
adjustment, I assume I am going to hose something one day unless I find a
solution. Are there other components are taking the beating in this "dry lifter
when it starts up" scenario?
Is replacing the lifters a reasonable option, or will that cause undue wear on
the cam and create a different, albeit still fatal, problem? Could the problem
actually be somewhere else in the oil flow path, and is only manifesting itself
in the lifter problem?
If I end up doing nothing, I would like to know what the consensus is, as to
which is the lesser of the two destructive evils, starting it up every day, or
every other day, and idling it at ~1500RPM for a fifteen minutes, or letting it
sit for three weeks, and then starting it up ,and driving it till the hellacious
noise drops away?
I know this is kind of long. Just wanted to get out the facts and avoid
confusion if I can.
Thanks for any advice. I appreciate it.
John
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