Mary,
If Tom is right about your problem being lifter noise then you might think about an oil change to 20W50 oil.  I do not know what you are running now or how old your present oil is but an oil change would be a cheap first step in fixing your problem.  You may also want to check out Stan's suggestion about adding Marvel Mystery Oil before you change the oil.  (Maybe Stan will e-mail you the procedure if he sees this.)  This treatment will clean your lifters etc.  
George
'85 Westfalia

> i'm on the road for the summer, first real trip with my 85 camper.  i've
> noticed lately that after an hour or so of driving and then sitting for a
> while, on restart she starts to sound a bit like a diesel.  after sitting
> overnight she sounds normal.  no lights flashing.  she was a little less
> than a pint low on oil after the drive from dallas to hot springs (plus
> additional meandering miles).