Hey everybody.

I'm having a new problem: The dreaded oil pressure light.

Today while driving to the airport the light came on yet again.  And it
didn't go off.  And I could hear a loud click-clacking sound coming from
the engine.  It definitely wasn't a normal sound.  Couldn't smell any oil,
didn't see any oil...nothing easily observable.

Thank goodness for AAA towing...

Here's the background:

On wednesday while driving on I-205 through Clackamas, my oil pressure
light went off.   Since I was in a rush to get the van in shape for a
hiking trip this weekend I took it to the mechanic.  He diagnosed the
problem as being a bad sensor and replaced it.  Everything seemed fine.  I
drove a few hundred miles this weekend.

Last night while driving home the oil light came on again, but only for a
few seconds.  A couple hundered yards later we hit a bump and the light
came on, but when we hit another bump a few seconds later it turned off
again.  Less than a mile from home I noticed a strange sound coming from
"back there."  A couple blocks later it stopped.  I checked the oil after
unpacking the van and found it a little low, but nothing noteworthy.

So where do I start investigating?

Thanks

--jay