Brian, if the valves are adjusted correctly (flat) and you have run it, the run it again, only to hear the lifter clatter again, then I suspect your engine has the typical vanagon "flat lifter" syndrome. For what ever reasons this is a characteristic of the engine. Maddingly frustrating. It appears to be caused by the oil pressure being lost in the oil galleries of the engine when it is shut off. A number of causes of this condition can occur. Improper filter with inadequate pressure relief spring can bring it on. A piece of trash in the oil in the lifter, any number of things. There are a numbers of ways to attack the problem. Some swear by including a pint to a quart of Marvins Mystery Oil additive to the engine during oil changes. For myself I find that religiosity with oil changes works .... using a Mahle filter of course!!I let the van sit a couple days and upon starting a had a noticeable clatter. I tried to ignore it and it did go away after about 20-some miles and hasn't returned in subsequent startups.
How about the clatter?
And sometimes nothing works but to change the lifter.
Good luck.
John Rodgers
88 GL Driver