Date:         Sat, 7 Sep 2024 19:03:05 -0700
Reply-To:     Rick Cooper <rick@WEBLEAF.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Rick Cooper <rick@WEBLEAF.CA>
Subject:      Hydraulic lifters

I'm dealing with noise emanating from the LH cylinder head on my 1987 vanagon with the stock 2.1 engine.  I'm sure it's valve lifters since my playing with valve adjustment effects the sound.  But my playing does not resolve it.

I've read a number of articles about these lifters. many of which have conflicting advice.  The one that seems the most logical to me is https://itinerant-air-cooled.com//viewtopic.php?t=11408, but I have so little experience that I really have no basis to prefer it to others.  These things are quite intricate and I am not sure even after my reading that I fully understand how they function.

In any case, my situation is this.   I'm only working on the LH side.   I previously removed the rocker arm, checked the straightness of the pushrods, and carefully reinstalled the pushrods and rocker arm to make sure that the pushrods were seated properly at both ends. I then dialed the adjustment screws in 1.5 turns and tightened the lock nuts.  But after a month of driving, the noise has not gone away.

So today I took another shot at it.  After loosening the lock nuts and turning out the adjustment screws until the are just making contact, I then try to screw them in the recommended 1.5 or 2 turns.  This works fine on the exhaust valves (which I believe are the ones on the ends) and I screwed them down by 1.5 turns.

The problem is with the intake valves, the two in the middle.  (Yes, I am working on the cylinders separately after setting the engine at TDC on each.)  In the case of both of the intake valves, as soon as I start trying to turn the adjustment screws the 1.5 or 2 turns, I notice that the valve itself is being pushed down, rather than the pushrod.  But if I turn them down the recommended 1.5 or 2 turns, won't that mean that these valves will be held slightly open?  (That would explain the lousy fuel efficiency I've been getting.)

Do I need to worry about that?  Will the hydraulic lifters adjust for this?  If so, why didn't the noise go away the first time I adjusted them?  Is there some other potential cause that I should consider?  Any advice appreciated.

Thanks, Rick