Date: Tue, 10 Feb 2009 21:37:05 -0600
Reply-To: joel walker <uncajoel@BELLSOUTH.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: joel walker <uncajoel@BELLSOUTH.NET>
Subject: Re: equals overcooling
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> John Muir talked about oil temps in his book but that was before
> synthetic oil.
> As I recall it was something to do with the oil breaking down when
> it got above 210ºf or so.
it does break down, but slowly. up to a point. when i used to have my
engine oil analyzed (got the idea from the helicopters in the army), i
found that at about 1800 miles on fresh new 30w oil, the viscosity
began to change. at 1800 miles, it was about a 34w oil. at 2500 miles,
it was a 40w oil, and at 3000 miles, it was a 46w oil. not to mention
the acids and crud (like silicon = sand, and carbon and other trash)
that was accumulating in it. there was enough carbon scattered around
the engine to turn nice pepsi-colored fresh oil into black 'used' oil
in just a couple of trips around town. :( anyway, i finally settled
onto about 2500 miles as the best choice for changing oil. plus it
divided nicely into the 'recommended' 7500 mile interval at the time.
when i changed to a 20w50 oil, the analysis folks apparently didn't
have the capability to tell what it was anymore ... it all came back
as a 50w oil in the tests. so i have no idea what happened on the
lower-temp side.
one thing i used to do, before gasoline got so expensive, was to go
out and drive 20 miles on the interstate on the weekends, to make sure
the oil got hot and boiled off the condensation and as much of the
acids and blow-by-fuel-in-the-oil as i could in that trip. it also
upped my per-tank mpg ... which was cheating, really. ;)
> I know John Muir's book was about air cooled VWs and some think it
> has no place in the modern water cooled VW world but I disagree.
a lot of his stuff is still relevant ... especially since our vanagons
have a lot of the same parts ..like rear brakes, cv joints, and a few
other things. and the philosophy of fixing it yourself without tearing
your hair out is still valid ...
a lot easier on a vanagon than it is on any 2008-2009 car. :( the
government (imho) and the car makers do NOT want you working on your
own car. the gumment figures you'll screw up the emissions; the car
makers want to make the money in their service departments.
unca joel
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