Date: Fri, 30 Aug 2002 08:07:44 -0400
Reply-To: Jay L Snyder <Jay.L.Snyder@USA.DUPONT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jay L Snyder <Jay.L.Snyder@USA.DUPONT.COM>
Subject: Re: Losing valve lash just after adjustment-why?
Content-Type: text/plain; charset=us-ascii
Run it for a while before re-adjusting the valves. Just long enough to get
it warm, but not hot. This will allow the lifters to pump up a little and
make adjusting easier (more defined zero-lash point). 20-50 oil does not
flow very well unless it is really warm outside. The fact that the
clearance is being lost tells me the lifters are continuing to pump up
further. Probably a good sign!
Jay
Tim Marciniak <tmarciniak@WI.RR.COM>@gerry.vanagon.com> on 08/29/2002
09:38:37 PM
Please respond to tmarciniak@WI.RR.COM
Sent by: Vanagon Mailing List <vanagon@gerry.vanagon.com>
To: vanagon@GERRY.VANAGON.COM
cc:
Subject: Losing valve lash just after adjustment-why?
Just did a compression test and two cylinders were low @ 100 and 106.
Heads done about 20,000 miles ago by a VW mechanic (not dealer). Van
has ran pretty well since them but lately I have developed a lumpy
idle and low manifold vacuum (10-12). I researched everything I
could find on the age old valve lifter issue including a call to Bob
at Boston Engine were I purchased my heads from. Followed his
instructions and adjusted the valves to .006 inch valve lash. I
adjusted both intake and exhaust when engine cold. Just to be really
thorough I rechecked them almost immediately after I adjusted them
(did not rotate the crank yet) and I swear I was back to zero
clearance so I readjusted again but did not recheck again cause i
wanted to finish and the mosquitos were really bad last nite. I also
checked all the valves for clearance before I adjusted and I could
not get a .006 inch feeler gauge in on any of them--I am suspected my
mechanic may of installed these heads the old way (preloading) and I
am starting to see problems now. My question is why did I lose this
.006 inch clearance just moments after I made the adjustment?
I did start the engine up after adjusting all the valves and it ran
pretty much the same, initially the manifold vacuum was about 14 but
then dropped to 11-12 after the engine warmed up and idle was lumpy.
Could it be the lifters are doing something strange? I am running
20W-50 for the summer.
Tim
--