Josh, I use Castrol 20w-50 in my '84.  I have had occasional loss of power
this summer when van has been at full operating temp such as when idling 5
min on a hot afternoon.  It clears up once I get van to over 35 mph.  I
relived the problem somewhat by a few drops of oil on the oil wick on the
distributor shaft.

John
----- Original Message -----
From: Joshua M Lee <josh@BEANSPROUT.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, July 21, 1999 2:46 PM
Subject: '84 Vanagon possibly dying. (Bertha)

> i posted about two weeks ago, but there have been a few developments.
>
> A little background:
> On the way back, roughly, from a 1000 mile trip, we were sitting in
traffic
> and suddenly the engine began idling high...and then higher and higher.
We
> got her off the road right before she was about to overheat.  We opened up
> the "hood" to see if we could see anything wrong with a quick inspection,
> but didn't notice anything.  We did notice that one of the coolant hoses
had
> slipped and fallen on the engine and was about 30 seconds away from
> meliting, which happened to us a week before.  So we decided we had to let
> her cool down, to protect what was remaining of that hose and get home.
> Four or five hours later, we checked the oil and put about half a quart
in.
> She started up and made it almost all the way home without incident.  Then
> we got to a highway with some fairly decent hills and she wouldn't make it
> up them in anything but 3rd gear going about 35 or so....the problem got
> steadily worse, but would get a little better if we stopped for awhile.
She
> is also leaking a small amount of oil/water from heads and main seal
between
> the blocks.  This is a list of things we have done, at the lists'
> suggestion, that have not appreciably fixed the problem:
>
> --replaced fuel filter
> --replaced plugs, ditributor cap and rotor (all in SAD shape)
>
> People have suggested the throttle switch(s), the catalytic converter, the
> clutch, the fuel injectors and/or the ECU...it seems to me however that
> except for perhaps the clutch, if any of these were the problem, that we
> would notice less gas burning, or the engine sounding like it was running
at
> less RPMs.  So, i wanted to ask everyone's opinion on the possiblity of
the
> oil being so contaminiated with water/gases that it is no longer properly
> lubricating, thus allowing the engine to expend too much of the energy
> produced in the form of heat.  She has been running a bit hot and in the
> past month has overheated a few times due to cooling system problems.
>
> What is the correct oil weight i should be putting in this engine and is
> there a decent workable aftermarket oil filter?
>
> i am not quite ready to give up on the engine, which some have told me,
> because she was running so well before the high idling problem, which is
as
> yet unexplained (any theories).
>
> Thanks!
> Josh