hi Ry,
just for funzies...
grab the crankshaft pulley and try to push it in and out........ ..engine off of course ( and no one sitting in the driver's seat either ) 
checking for end-play.
there shouldn't be any easily detectibible end-play.

not likely that it'll move excessively, but it's a simple test that by remote chance could reveal something. 

usually you can tell gear oil from engine oil by smell.
the Redline MT-90 gear oil I'm using lately seems engine oil colored, more or less. 

  ----- Original Message ----- 
  From: Ry 
  To: Scott Daniel - Turbovans 
  Cc: vanagon@gerry.vanagon.com 
  Sent: Wednesday, June 30, 2010 1:23 PM
  Subject: Re: Re: Oil leak since rebuilt 2.1l installed

  Thanks for the free brain cycle time :)

  The reason I think I know it's not transmission oil is color, i have that redline synthetic and that as you probably know, has a definitive color to it.  

  I'll drop the trans next time i have a 4 day weekend to spare and some spare parts.

  flywheel was preinstalled, i certainly hope it was properly installed but I should check it.  i've never done a rear main seal job.  I've done seals when changing wheel bearings.  

  carry on,

  -Ry

  On Wed, Jun 30, 2010 at 2:46 PM, Scott Daniel - Turbovans <scottdaniel@turbovans.com> wrote:

    hi,
    it was clear you were talking about the engine-transmission junction area.

    yeah, there shouldn't be a drop there with a fresh engine.
    and if you're sure it's engine oil.. ..  Just because trans is rebuilt that doesn't mean 'for sure' it can't leak some there .
     In my brain I never think 'oh that's new, can't be that' ..
    I think the opposite ...that was just worked on ....the problem could be there .
    I always go for the most recent work when there's an issue ...I often find 'the issue' there.

    things that come to mind if it's engine oil -
    rear main oil seal of course.
    anything to do with end play of the crankshaft and that whole end-play shim/rear main seal area.

    oh ...here's one..........I've seen this one ...no lock-tite on the flywheel bolts ....oil will gradually migrate up the threads of the flywheel bolts if there is not a sealant or lock-tite on the bolt threads.  They should always bet lock-tited in of course.
    there's an o-ring on the crankshaft side of the flywheel...that's gotta be there.

    anything to do with crankcase pressure and not venting/relieving pressure properly.
    Waterboxers seldom have that problem ...but the oil tower ...there are moving parts in there...
    spring and some other part ...if that was all clogged up , could be a factor.

    doubt it's the oil itself, but consider that....brand, grade, and viscosity.

    but if the engine is new ...
    it sure shouldn't do that.  If it did that in a year say ...mabye ok,
    but new.....shouldn't be an oil drop there.
    it should be either ... a seal issue, or what the seal seals against .....or breather/crankcase pressure issue. ...somewhere in there.  Even excessive main bearing oil clearnce could cause it.  Or cheap rear main seal. The good ones are all red, or have a red lip where they actually do the sealing ...the all black ones are not so hot, but they should work find for a while .
     If it was mine, I'd be taking the trans or engine out to look at things very carefully, much as one hates to do that over one small drop.

    Scott
    www.turbovans.com

    ----- Original Message ----- From: "Ry" <rylincoln@GMAIL.COM>
    To: <vanagon@GERRY.VANAGON.COM>

    Sent: Wednesday, June 30, 2010 11:59 AM
    Subject: Re: Oil leak since rebuilt 2.1l installed

      when i say rear of engine i mean where it mates up with the transmission,
      oil pump is on the "front" of the engine. sorry for the confusion, I still
      think of the engine seperate from the van so i don't get confused on front
      and rear designation.

      Definitely not transmission oil, i have a rebuilt trans too, replaced at
      same time as engine.

      No oil on the engine lid, only on the bottom of the engine where
      transmission and engine meet at the center of the case.

      I'm not calling out the rebuilder on the list, that would be poor form, but
      I didn't rebuild it, was professional rebuild.

      this is the area where it drips once or twice when stopped.
      http://picasaweb.google.com/lh/photo/3L4SAvf39FK2iLzL_frNBw?feat=directlink

      -Ry

      On Wed, Jun 30, 2010 at 1:27 PM, Scott Daniel - Turbovans <
      scottdaniel@turbovans.com> wrote:

        'carry on' ...lol.

        make sure it's not transmission oil ...could be.

        if it is engine oil...
        no, should not have a slow leak or any drips there.
        I'd say the only acceptable level of leak there would be one drop of oil
        sitting on the engine ..at the most ...and no drops on the ground ...
        shouldn't have that with a new engine.

        ----- Original Message ----- From: "Ry" <rylincoln@GMAIL.COM>
        To: <vanagon@GERRY.VANAGON.COM>
        Sent: Wednesday, June 30, 2010 9:59 AM
        Subject: Oil leak since rebuilt 2.1l installed

         So, I'm not terribly worried about this but am interested in the opinions

          of
          the hive mind here.   I installed a rebuilt 2.1l engine ~3,500 miles ago.
          Pretty much since the beginning there has been a slow oil leak from the
          rear
          of the engine.  I assume it's the rear main seal(what else is back there?
          It's not enough to warrant needing to add oil between oil change
          intervals,
          there are maybe 1 or 2 drops of oil on the ground when parked for several
          hours.

          Oh no woah as me, I know.... this is NOT a major problem, but I sure would
          like to have NO oil leaks, is this unreasonable?  Do many people have
          little
          leaks they just ignore?

          I reckon I'll just live with it for now.  I have an oil pressure gauge and
          oil temp gauge along with an external oil cooler so I should get warned
          quickly of any lubrication troubles.

          carry on,
          -Ry