Hello,

I have followed oil filter testimonials and experiments on this list and in
the media for years.  While I understood that a better filter is a good
thing, I couldn't figure out which filter was "better."

This note is about a specific observed failure.

A short time ago, I noticed bearing knock for a second or two just after
starting my Vanagon after not using it for 10 hours or more.  I immediately
suspected the anti-drainback valve in the oil filter.  I changed the oil
filter Saturday, and after the usual startup and check for leaks, the
Vanagon sat until this morning.  No bearing knock on startup.

I looked at the used filter, and I understand how the anti-drainback valve
works, but I couldn't see any obvious physical problem with it.  The famous
Mopar oil filter study says to expect this failure from a Fram (yes it
was), but I don't see how the Fram design is flawed other than the valve
flap is a cone shape rather than flat as it is in other filters.  (I
disregarded the "rough metal backplate" words since the plate referred to
looks the same as used in other filter brands.)

Thanks for listening.

Mike  '84 GL  '58 Isetta