Date:         Wed, 9 Dec 1998 15:41:32 -0800
Reply-To:     YauMan Chan <YauMan@CCHEM.BERKELEY.EDU>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         YauMan Chan <YauMan@CCHEM.BERKELEY.EDU>
Subject:      Oil Filters Again - Clarification
Comments: To: vanagon@vanagon.com
Content-Type: text/plain; charset=US-ASCII

Fellow Vanagonians,

After my last posting the few e-mails I got prompted me to post this clarification.  

When I say that our Vanagon's oil filter is tilted on it's side, I overstated the angle.  The Vanagon filter is tilted about 45 degrees as compared to the Rabbit/Golf which is tilted only very slightly and practically verticle.  The difference still stand in that while the oil will not completely drain out of the filter chamber, enough oil will drain out.  It should also be noted, that not only do you want to keep the oil filter filled with oil for tomorrow morning's startup, you also want all the oil in the oil passage ways fed by the output of the filter also fillled with oil.  Without an anti-drain valve, as soon as back flow start in the filter, the oil accumulated in the bearing oil passage way will  be siphoned out thus increasing the detrimental effect of running your Vanagon engine dry for the first few minutes.  In cars like the Nissan or Hondas where the oil filter is flat on it's sides or some Toyotas where the filter is mounted upside down, the anti-drain valve is actually built into the engine in some models.  

How can you tell if the filter you are using has anti flow back? Very easy if you change your own oil  filter.  Warm up your engine then turn it off and let it sit for about 15min  It will cool off the oil enough to not burn you when you change the oil and give the oil enough time to drain back if there is no drain back valve.  Next, without removing the oil filter, drain the oil.  Then, slowly unscrew the oil filter.  If your oil filter has anti-drain back, you  will see oil flowing out of the filter top as soon as your crack the seal with the engine.  It is messy.  Messy is good.. Oil is being held at some slight pressure in the filter until you released it ..your oil filter has anti-drain and it's working.  If there is no oil escaping from the top when you unscrew the filter, all the oil has drained back into the sump.. you have the wrong filter for your baby!!

Sorry for another long posting.. I hope this info is relevant to owners who want to keep their finicky but lovable van alive and well!

Yau-Man Chan
87 GL