I posted a while back on a strange and very loud screeching noise I was
getting from somewhere on/in my aircooled engine, coupled with a
perceptible loss of power. The noise only occurred when throttle was
applied under load. Based on advice on this list, I changed the fan
belt. The noise was still there.

Then, thinking it had to do with the distributor, I popped that item out
and inspected it for a broken advance mechanism which might cause the
weights to touch the distributor body. However, in the design of the
distributor, there are posts built into the weight mechanism that
prevent the weights from flying out too far, in the event a spring
breaks.

What I did notice, however, was that the Hall Effect rotor (my '82 is a
California van with electronic ignition) had what looked like a wear
mark on it all the way around its circumference, and there was virtually
no clearance between it and the stationary magnet. I theorized that when
throttle was applied, the distributor shaft moved just enough to cause
these parts to rub at high speed.

I opened up this clearance a bit and reinstalled the distributor. The
noise is gone. I will be test driving the van today to see if it
feels/drives normally. The loss in power could possibly be attributable
to the Hall Effect rotor rubbing on the stationary magnet, which might
have altered the ignition timing.

Weird stuff, but I need to sell this vehicle, so I'm trying to find and
address the various "issues" it may have. A major oil leak turned out to
be the oil filter adapter gasket- it was leaking under pressure like
crazy, but is now fixed. Hopefully, these two problems are the extent of
my van's "issues."

Anyone experience a similar problem?

Dan Schmitz

'82 2.1L Adventurewagen (for sale soon)
'87 Westfalia (as soon as I can get to Grand Junction CO to pick it up)
'75 Porsche 914