Through all that text and history, I don't remember you saying that
you had replaced the big O ring between the oil cooler and the
block.  they are notorious for cracking with age and not terribly
expensive to buy, even from the dealer.  I think you have to pull a
couple of the short small hoses off to get the cooler off, so pinch
the hoses to prevent the coolant from leaking everywhere.  Using a
Fram filter is a no-no for sure, so maybe when you do decide to
replace the cooler o ring, you can put a Mahle or Mann filter on there.

Others may have additional and/or better advice.  the oil might be
coming from the small o ring that seals the dipstick holder,
especially if the bracket is loose.

DM&FS

At 06:56 PM 1/12/2009, A J wrote:
>OK here is the background. 1991 Vanagon GL it has 40,000 on a "crate"
>replacement engine. Runs great,but. About 3-4 months ago ,the first time
>it happened, I was driving along about 60 mph and noticed that the rear
>window was "filming" up and there was an occasional puff of smoke,
>dropped to about 50 and went straight to the driveway.
>
>The next day went out and cleand the entire bottom of the motor with
>carb cleaner and let it sit for a day, no drips. So went for another
>drive, about 5 minutes into the drive the same thing happened. This time
>I sprayed off the bottom while it was warm and looked for leaks, nothing.
>
>Next day I put some clean cardboard down on the drive and then did an
>short run through the neighborhood came back and parked on the
>cardboard. Most of the dripping was at the rear cross motor mount but
>there was some at the side by the valve cover. I replaced both vaqlve
>covers figuring that if they were leaking the air blowing by would
>deposit the oil on the crossbar and spray it on the rear deck.
>
>Another drive more oil.
>
>I cleaned it all off again and this time put down cardboard but didnt
>drive just ran it in place. Nothing for about 4-5 minutes then it
>started leaking and seemed to be coming from the motor mount. Could not
>see any oil from the top of the motor only from the bottom. From the top
>looking down it is all clean and neat looking like nothing is leaking at
>all so it is not being flung through the compartment by the belts.
>
>I figured that the only place that I couls not see was the probable
>area, the crankshaft seal. I ordered a nea seal, replaced it and went
>for a drive, yep in about 5 minutes it started spraying the rear of the
>van just like before.
>
>I cleaned it all off and let it cool off. The next day I went out with
>the cardboard and with it running in place and changing rpm between 2000
>and 3500 it was a good five minutes before I saw it start leaking. I
>cant directly see it but it is leaking on to the left side of the mount
>and dripping off the bar, The rear of the motor is not wet and there is
>no oil leaking down the side. This wont leak until the motor heats up.
>
>I am wondering if it is possible for the oil cooler to leak by spraying
>the oil onto the mount figuring that after the motor heats up it opens
>the gap between the gasket or whatever, sound plausable? If I remember
>correctly this started  after I changed the oil and installed the fram
>filter. I wonder if it is possible for the filter to not bypass and then
>create enough pressure to force the oil out?
>
>There is no oil in the cooling system so I believe the oil cooler is not
>leaking internally but wonder if it is possible for oil to leak out
>between the cooler and the block, well not leak but spray. Would it be
>possible to tighten the cooler to the block by removing the filter and
>torquing the bolts or should it be removed and a new seal installed? Or
>should I just consider something else because there is simply no oil at
>all dripping off the filter or the block just from the bar the the motor
>mounts to. Is it possible that the oil could be coming from the motor
>mounting bolts.
>
>Keep in mind that it does not drip and wount drip out until the motor
>reaches temp and will stop as soon as it is shut down. Any help,
>opinions, or guess appreciated.
>
>Thanks,
>
>A J