I had an expensive-sounding clacking noise start up on the engine
today. The noise is a repetitive clack which increases in frequency as
the engine rpms increase. RPMs don't seem to affect volume or pitch.
The noise can be heard inside from the driver's seat very clearly, and
is louder outside the car.  It seems to be located behind the
transmission but in front of the pulleys. Also, it is very loud when
underneath the van engine compartment. The noise seems to be located
in the engine.

The noise started when I left work today and drove about a mile home.
When I heard the noise, I gently drove to the house. When I drove to
work today, the noise wasn't present.

When I got home, the noise starts up each time. I noticed that I had
taken off the oil-filler cap and not replaced it, so it was off for
the 2 miles roundtrip today. Fortunately, it was still sitting on my
rear bumper when I got home, so I replaced it, but still the clacking.

Fearing something valve or pushrod related, I pulled the valve covers
off to inspect the heads. Nothing seemed amiss, but on the driver
side, a fair bit of oil poured out after I removed the valve cover.
None pored out the passenger side valve cover.  I couldn't tell much
more than that, but I'm no expert.  Right now I'm looking for advice
on how to diagnose the problem.

Thanks for your thoughts,

Jarrett Kupcinski
89 Westfalia